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                         COLORADO WILD FLOWERS


                            MUSEUM PICTORIAL

                                ROBERTS

                            Copyright 1953,
         by Denver Museum of Natural History, Denver, Colorado

              Lithographed in the United States of America
                 by Bradford-Robinson Printing Company,
                            Denver, Colorado




                           _Acknowledgments:_


The original color films used for the plates on pages 15 and 26, were
heretofore reproduced in different form in “American Wild
Flowers”—Moldenke, published in 1949 by D. Van Nostrand Co., New York,
with whose permission they are again reproduced here.

The pen and ink diagrams and sketches on pages 3, 60, 61, 62 and inside
back cover, were prepared by Mary Chilton Gray, of the staff of Denver
Museum of Natural History.




                              Lily Family
            Yucca or Spanish Bayonet, _Yucca glauca_, NUTT.


⇐FRONT COVER

Flowers, closely arranged along a tall woody bloom stalk, are each
formed by 6 petals and sepals (perianth segments) surrounding a large
fleshy pistil. The 3 outer segments often have mahogany brown shading on
the back, the 3 inner are creamy white, or greenish white. They look
like drooping bells in the daytime, but spread to a total width of 3 to
4 inches when fully open in late evening. Pollination is accomplished
only by the deliberate work of a _Pronuba_ moth. Total height of plant,
including blossom stalk, is about 4 feet; leaves narrow, stiff and
yellowish green, with a sharp spine at tip. Grows on plains,
particularly in sandy areas, and extends into foothills. Blooms
June-July.




                   SOME COMMON COLORADO WILD FLOWERS


                                  _By_
                        Harold and Rhoda Roberts




                                FOREWORD


The generous acceptance of the first seven numbers of MUSEUM PICTORIAL
convinced the Trustees of the Denver Museum of Natural History that the
publication is filling a definite need in the field of natural history
reports. The subjects are so varied that a wealth of material is
available.

The present issue is the first printed in color, and will, we hope, be
followed by others. The authors, Harold and Rhoda Roberts, probably are
the foremost photographers of wild flowers of Colorado and the
Southwest. This field work has carried them from the tops of the highest
mountains of Colorado to the depths of Death Valley. Their outstanding
Kodachrome slides have been shown to many audiences and have appeared in
publications. It is hoped that Museum Pictorial No. 8 will be the first
of a series on Colorado wild flowers by the authors, which may
eventually be compiled into book form.

Harold Roberts, prominent Denver attorney, is a Trustee of the Museum,
and chairman of its Building Committee.

                                            Alfred M. Bailey, _Director_

  _Museum Pictorial No. 8
  Published May 30, 1953
  Denver Museum of Natural History
  Denver, Colorado_


The purpose of this booklet is to portray a few of the common
wildflowers of Colorado in such form that they may be recognized and
their names learned without the use of any botanical key. The color
plates here published show fifty different flowering plants, each of
which grows in abundance in some part of this state. Most of them are
found also in other areas, particularly in the Rocky Mountain states.
With the description of each plant, some reference is made to the life
zone in which it grows, but no attempt is made to give the geographical
extent of its range. In every instance the photograph reproduced was
taken on Kodachrome film of a living plant in its natural setting. All
of them are shown in full bloom as we see them in Spring or Summer,
except milkweed, page 43, and cattail, back cover. These appear in seed
as we find them along the roadsides in October.

The flowers are here arranged in substantially the order that the
families to which they belong appear in most botany manuals. Some
references to these plant families, and to the genera and species into
which they are subdivided, will be found on page 57. With each plant we
have given the common name most familiar to us. As there is little
uniformity in common name usage, others may know them by other names. We
have added in each case, in italics, the Latin botanical name, with
abbreviated identification of the botanist first using that name. The
English form of the family name is also given. We have tried to select
flowers representing as many plant families as possible, and among them
to cover plants from different altitudes and from different types of
soil and growing conditions.

Some of these photographs were taken at close range, with a long focal
length lens, to show on a large scale the beauty of very small flowers.
Others were taken with different equipment so as to include the form of
the complete plant and show plainly its natural setting. In all cases
the size of the flower and of the entire plant are given in or may be
inferred from the descriptive text. The figures used are approximate,
and considerable variation from these sizes will be found. The colors
are as accurate as colorfilm and high class press work can make them.

The pictures here reproduced were all taken by the authors within the
past twelve years. Most of the plants were found within a few hundred
feet of some well traveled road. A few of the pictures were taken in
adjoining states, but in every such instance the species shown is found
in the same sort of environment in Colorado. Many of these flowers are
reproduced as part of the setting in habitat life groups in the Denver
Museum of Natural History. Look for them there, and also get acquainted
with them in their native haunts. They add decided interest to outdoor
ramblings.




                               LIFE ZONES


    [Illustration: Life zones]

  14,431′
      Alpine
  11,600′
      Sub-Alpine
  10,000′
      Montane
  8,000′
      Foothills
  5,500′
      Plains
  3,500′

Climate, which is a composite of prevailing temperature, length of
season and average moisture, is the chief factor in deciding where
plants of any given species can grow and propagate. Soil type also plays
a part, and if extremely unfavorable may totally exclude some species of
plants from a large and otherwise favorable area, but in general, soil
is the minor factor. In Colorado, climate is largely determined by
altitude, so here, as we pass from one elevation to another, we find
plant life arranged in horizontal layers or zones of the sort
illustrated in the above sketch. The thinness of air, in the sense of
less oxygen per cubic foot of air, that goes with high elevation, seems
in itself to have little effect on plant life, but the prevailing cold,
the long period of snow cover, and the increase in annual precipitation,
that go with elevation in our mountains, do have a profound influence on
plant growth. High latitude has much the same effect as high altitude,
so that the timberline conditions we find in Colorado at from 11,000 to
12,000-foot elevations are very similar to those existing at sea level
near the Arctic Circle. Growing conditions, and prevailing plant
species, at these widely separated places, are, for this reason, much
alike.

These zones of life have no sharp boundaries, but tend to intergrade
into each other. Many species of plants normally inhabit parts of two or
more zones, and local conditions may so influence climate that
particular species of plants will be found growing at lower elevations,
or at higher, in one part of the state than in another. Generally,
however, in Colorado like elevations result in plant populations of
quite similar makeup, even though a whole range of mountains or a deep
wide valley may lie between. The principal factor causing exceptions to
this rule is the tendency of many areas in western Colorado,
particularly those between about 6,000 and 10,000 feet in elevation, to
receive greater average annual precipitation than is received by
corresponding areas east of the Continental Divide. As a result of this,
many species which in eastern Colorado occur only in moderately high
elevations will be found clear down in the foothills in western
sections.

The individual life zones of Colorado are illustrated and described on
the next five pages.




                                 PLAINS


    [Illustration: {uncaptioned}]

All of Colorado lying east of the base of the mountains, as well as
large areas in western Colorado lying along the course of the Colorado
River and its main tributaries, are within the life zone commonly known
as the Plains, and referred to in technical books as Upper Sonoran.
These areas are mainly below 5500 feet in elevation, and are relatively
flat. Clay soils are the rule, with local sandy spots. The rainfall
throughout this zone is scanty and irrigation essential to general
farming. These conditions have restricted the native vegetation
throughout this zone to species which can tolerate long periods of
drought, and thrive on sunshine with heat in summer and cold in winter.
A surprising number of species of flowering plants live and thrive on
these very conditions. We rarely find them in colorful masses, single
plants or small colonies being the rule.

Originally native grasses covered this zone with a fairly tight sod,
broken, however, by windblown patches and cut by arroyos. Live streams
were far apart. Trees were absent except for cottonwoods and a few box
elders along water courses. Settlement has brought roads, ditches,
cultivated fields and a large amount of livestock. These acts of man
have made life hard for some native flowers, but for most species,
living opportunity has been increased. The plains are flowerless only
for those who fail to pause and search.

The detailed growth patterns or specialized mechanisms by which the
various plains flowers resist drought, and so get a chance to live, are
numerous. In general they do one or more of these things: rush through a
short individual life cycle from seed to seed so timed that the new seed
crop is set before the heat of summer is far advanced; conserve the
limited moisture their roots gather by having few leaves and defending
them from animals by thorns or toughness; or, spend a large part of
every year, especially the dry, hot months, as a dormant bulb or buried
root stock.

The picture at the top of this page shows a plains area just at the base
of the foothills near Denver. It looks barren, but many species of
flowers can be found there in May and June.




                               FOOTHILLS


    [Illustration: {uncaptioned}]

Long strips of land from 5500 to 8000 feet in elevation lying between
the plains and the mountains, and filling in with rough hills and
valleys the spaces between mountain ranges, comprise a life zone known
as the Foothills, and named, by naturalists, the Transition zone. In
this zone much of the soil is filled with gravel and weathered rock
detritus washed down from higher land or left there by ancient glaciers.
Total annual rainfall in this zone is higher than on the plains, and the
broken character of the land gives protection from storms.

A greater number of species of flowering plants can be found in this
zone than in any other single zone. Local conditions of soil, water and
sun exposure vary widely, and these variations offer favorable living
conditions to different types of flowering plants and to the numerous
shrubs that grow here. Many species of wild flowers which grow on the
plains extend into the lower parts of this zone, while other species
found in the higher mountains reach down into it, especially along
streams.

The chief native trees of this zone are yellow pine and, along streams,
narrow leaf cottonwood. Scrub oak covers many hillsides with dense
growth, junipers are locally plentiful, and aspens reach down from
higher elevations. This tree population attains forest proportions only
here and there so that open places for wild flowers are abundant.

In Colorado, visible spring comes earlier in this zone than on the
plains below. Sheltered slopes facing the sun pick up the earliest flush
of spring green, and by the end of March the very first flowers may here
be found in bloom. Late April, May and early June bring the main flower
crop. Mass color effects may then be found such as several acres blue
with Larkspur, or a whole hillside dotted with red clumps of Lambert’s
Loco. The main show is over by mid-July, though asters and
sunflower-like composites keep the roadsides colorful till frost.

The picture at the top of this page shows a foothills area near Golden.
In good years these hills are rich in flowers by early May. A half hour
walk then will frequently yield 30 species or more.




                                MONTANE


    [Illustration: {uncaptioned}]

The great mid-sections of our high mountains, lying between 8,000 and
10,000 feet in elevation, make up a life zone called Montane, also known
as Canadian. Since most of our Colorado mountains are granite, the
typical soils in this zone are granite gravel. Some mountains, however,
are faulted blocks of sedimentary rock which have weathered into clay
and sand soils. The annual rainfall in this zone is over double that of
our plains. This has resulted in forests of lodgepole pine, aspens, and
of several species of spruce, with stream banks lined with willows and
water birch.

This abundance of vegetation has produced enough humus to build rich
black soil in the bottoms of the narrow valleys. In this zone grow a
wealth of flowering plants. The principal adverse conditions against
which they struggle for existence are: a fairly short season from spring
melt to fall freeze; and more tree shade and more competition from tree
and shrub roots than they would choose. The steep hillsides in this zone
may be quite rock covered. Between the rocks small amounts of good soil
may form, and under loose rocks moisture stays for a long time. Trees
thrive on these hillsides, but in open spots and beside rocky outcrops
flowers get their chance. The columbine grows in perfection in this
zone, extending downward into the foothills and upward to timberline.

The building of highways in our mountain areas has introduced new
conditions of which some plants are quick to take advantage. The
stirred-up soil of new road fills and drainage channel construction will
be colorful with fireweed, purple fringe, brown-eyed-susans, with here
and there penstemons and asters by the second or third season of their
use. Local irrigation accomplished by highway drainage and the use of
snowplows, as well as distribution of seeds by animals and even by cars
that use the roads, all play their part in this quick restoration of
life in the soil that has been torn up.

The picture at the top of this page was taken near Mary’s Lake in Estes
Park. The mountain shown is Twin Sisters. Its slopes are a fine hunting
ground for flowers.




                               SUB-ALPINE


    [Illustration: {uncaptioned}]

Above 10,000 feet the pattern of life changes. Until timberline is
reached at about 11,500 feet, this band of mountain country is called
the Sub-Alpine or Hudsonian life zone. Soil and moisture conditions are
almost as favorable as in the lower montane zone, but here the snows of
winter stay late, especially on north slopes, and frost may come even in
mid-summer. The race to ripen seed, before winter comes, is intense, and
the seeds, when produced and scattered, face special problems of
germination and survival.

The trees of this zone are largely Engelmann spruce, limber pine and
alpine fir. Some thick forest stands exist, but the main pattern is
small compact tree groups—one or more big seed-trees surrounded by
younger offspring—with open patches of grass between. Perennial
flowering plants, springing from woody root-crowns have special
advantages here, though some annuals thrive, especially if they can get
started in the fall and remain dormant under snow till spring. Melting
snows in May, June and early July give natural irrigation to large areas
of this zone. Competition with sedges and grasses and ability to stand
light frost are problems for the plants that live here. Many typical
alpine plants of the next higher zone work down into these sub-alpine
meadows.

The picture at the top of this page was taken just west of the Poudre
Lakes in Rocky Mountain National Park. Lake Irene is in the foreground.




                                 ALPINE


    [Illustration: {uncaptioned}]

From timberline (about 11,500 feet) up to our highest Colorado mountain
summit (Mt. Elbert 14,431 feet) climate is too severe for any trees.
This condition marks these areas off as a separate life zone called
Alpine or Arctic. Soil forms only slowly on these rocky summits, but
mosses, lichens, sedges and grasses have been here for ages of time, all
of them patiently building humus. Erosion carries less soil away from
the tops than it does from the lower hillsides. So in the spaces between
the barren looking rocks, good soil exists, and water, though mainly
falling as snow, and not quite as heavily as in the sub-alpine zone
below, is adequate for plants. Here grasses, sedges, a few dwarf shrubs
and herbaceous plants have all the sunlight to themselves without tree
competition. The ever-present adverse condition is low temperature,
frequently with strong wind.

It is a land of tough dwarf things. Perennials are the rule, though
annuals are found. Low woody mats with basal leaves and flowers only a
few inches high are a common pattern. Bulbs and tubers wedge themselves
between rocks, out of reach of ground squirrels, if possible. When
spring comes with a rush, usually late in June, these dormant plants
burst into life in the days of longest sunshine. Shoots of new growth
erupt from the ground with buds all formed ready to open. By the end of
July the seed crop is largely mature, and by mid-August the browns and
crimsons of fall colors in leaves and grasses spread a Persian carpet
over these heights. Warm days from then till winter are days of
germination for newly scattered seeds and, for established plants,
preparation of buds for next year.

It is in this zone of harsh living conditions that some individual
plants probably attain greater age than is normally reached by plants of
the lower life zones. We know of no statistical study to support this
statement, but observation of mats of moss campion, or of tufts of
alpine spring beauty, or of scarred old crowns of alpine forget-me-not,
indicates that they have safely survived the snow cover of a great many
alpine winters.

The view at the top of this page is from Trail Ridge in Rocky Mountain
National Park. Longs Peak is in the distance. In mid-July these
foreground slopes are a garden of alpine flowers.




                              Lily Family
                Sand Lily, _Leucocrinum montanum_, NUTT.


    [Illustration: {uncaptioned}]

Flower is an inch in diameter, of 6 petals and sepals all alike
(perianth segments) united at their base into a tube over an inch long.
Several of these rise from the buried crown of the plant, as do also the
leaves, ⅜ inch wide and over 6 inches long, resembling heavy curved
blades of grass. The matted, cordlike roots store, through the long
dormant period, the starches and sugars needed for rapid Spring growth.
Grows in sandy soil in plains or low foothills. Blooms April-May.

When sand lilies begin to dot the gray plains with their singularly pure
white stars we can know that the season of growth and color is
returning. We called them Mayflowers and hoped they would be in bloom
for May-baskets. They usually were—along with Johnny-jump-ups (little
yellow violets) and sprays of pepper and salt parsley. To pluck them one
by one and suck the drop of nectar from the long white tube is one of
the delights of childhood. The plants are crowded with flowers during
the blooming season, but, when it is over, disappear completely from the
scene.




                              Lily Family
                 Wood Lily, _Lilium umbellatum_, PURSH


    [Illustration: {uncaptioned}]

The flower, of flaring trumpet shape 3 inches in diameter, is formed of
6 petals and sepals, all alike, (perianth segments) tapering at both
ends. Color varies from rose-red to red-orange. Stem 15 to 30 inches
high, bearing a single flower (occasionally 2 or more) and several
whorls of leaves, comes from a round bulb. Picking the flower usually
kills the bulb. Grows in rich soil in partial shade near streams,
montane zone. Blooms July.

This is one of the most sought-after and breathtaking of our mountain
flowers. It used to grow in abundance, then almost disappeared due to
excessive picking. Now it is returning in secluded sylvan places. It
prefers moist, shady banks where its brilliant color lights the shadows
like a flame. The young flowers, with their big dark anthers, are the
brightest. As they fade, the anthers shrink and turn dull orange and the
flower has a tendency to become spotty. If you have the good luck to
find these lilies, stop and enjoy them in their woodsy background—but do
not pick any to take home.




                              Lily Family
               Mariposa, _Calochortus gunnisonii_, WATS.


    [Illustration: {uncaptioned}]

Flower, more than 1 inch in diameter, is formed of 3 perianth segments,
which are narrow, greenish and sepal-like, and 3 segments which are
broad, showy and petal-like. On the inner surface of these latter, near
the base, are large, hairy glands of dark color. Stem is slender, 8 to
20 inches tall, with few linear leaves, and comes from a deeply buried
corm. Grows in fairly heavy clay soils on open grassy slopes in
foothills and lower montane zones. Blooms June-July.

The name mariposa recalls to us the high flat tableland of Mesa Verde
with thousands of these delicate lilies floating above the other flowers
like butterflies, as the Spanish name implies. Our species is one of the
most beautiful, with its tall stem and subtle coloring resembling a
small white tulip with grass-like leaves. Other species are creamy,
yellow, orange, pink, lavender, gray; some of them quite small, with
pointed hairy petals. Journeys to many interesting places will go with a
search for the mariposa in its infinite variety of color, shape and
habitat.




                              Lily Family
            Glacier Lily, _Erythronium grandiflorum_, PURSH


    [Illustration: {uncaptioned}]

Flowers, 1½ inches across of 6 bright gold perianth segments, all alike
and strongly re-curved, nod, singly or in twos or even threes, at the
top of a naked scape which rises from the deep-seated bulb. The 6
stamens, each tipped with a large yellow anther, surround a prominent
green style and hang downward. Plant is about 10 inches high, with only
two broad green leaves which sheath the base of the scape. Grows in
sub-alpine zone extending through montane zone. Occurs only on the west
side of the Continental Divide (except for a few limited areas
immediately on the east side). Blooms immediately after snow melts,
which is June in high places.

Below the snowbanks on Mt. Audubon, near Thunder Lake in Rocky Mountain
National Park, on slopes near Rabbit Ears Pass, and in many places on
the western side of the range, early summer brings one of the finest
flower shows in the west, which it is no exaggeration to call the “field
of the cloth of gold.” The glacier lily (also called avalanche or snow
lily—or, oddly enough—the dogtooth violet) begins to bloom right at the
foot of snow banks and follows the retreating ice up the mountainsides.
We have seen acres where it was hard to walk without stepping on several
plants, particularly in the northern mountains of Wyoming and Montana.




                             Orchid Family
           Yellow Lady’s Slipper, _Cypripedium calceolus_, L.


    [Illustration: {uncaptioned}]

Flower, usually solitary, is shaped like a Dutch shoe about 2 inches
long. The sac-like toe part, formed by one of the 3 petals, is bright
yellow with greenish sheen, the other 2 petals, much narrower, extend to
the sides and are often twisted and streaked with brown. Plant is about
10 inches tall, with broad lance-shaped green leaves which enclose the
lower part of the flower stem. Grows on moist but not wet slopes in
montane zone. June.

In not too open aspen glades in middle elevations, a privileged seeker
after beauty may find this yellow lady’s slipper, largest of our native
orchids. It is one of several species of _Cypripedium_ (the name meaning
shoe of Venus) and is sometimes called moccasin flower. A smaller,
daintier orchid, the pink _Calypso bulbosa_, is more widely known. This
latter likes half sunny edges of our lodgepole forests, being quite
dependent on the humic acid of the needles. Often in large groups along
the remnants of a decayed tree trunk, they make an entrancing sight,
resembling fairy dancers. These are but two of about a dozen orchids
that grow wild in Colorado.




                          Four o’Clock Family
              Prairie Snowball, _Abronia fragrans_, NUTT.


    [Illustration: {uncaptioned}]

Individual flowers are formed of a slender calyx tube, 1 inch long,
flaring at its mouth into 5 white, petal-like lobes to make a tiny
salver ¼ inch across. They have no true petals. Numerous such flowers
are clustered to form the surface of a ball about 2 inches in diameter.
Plant has reddish stems, somewhat hairy, that creep on the ground, with
fleshy (succulent) green leaves arranged in opposite pairs. Grows in
plains on sandy soil. Blooms May-June.

Every plains child knows the prairie snowball—inhabitant of vacant lots
in towns, and of dry wind blown flats “in the country.” The cluster of
starry flowers is indeed round as a snowball and as white—the dark green
leaves are in sharp contrast with the bright red stems. The fragrance,
almost cloying it is so sweet, perfumes the air of early summer,
especially as evening coolness comes. The reddish-purple sand verbena of
the southwestern deserts and coastal sand dunes, _Abronia villosa_, is
also of this genus. The resemblances are quite apparent.




                            Buckwheat Family
             Sulphur Flower, _Eriogonum umbellatum_, TORR.


    [Illustration: {uncaptioned}]

Numerous flowers, each formed of 6 minute yellow perianth segments, are
grouped in round tight clusters at the ends of slender pedicels, several
such clusters radiating to form a flat-topped head (umbel) 4 inches
across. These heads are borne on erect hairy leafless stems (scapes), 8
to 15 inches tall. Oblong leaves about 1½ inches long, form a green mat
on the ground. Grows on open dry slopes of foothills and lower
mountains. Blooms June-September.

Many Species of _Eriogonum_ are found in Colorado, some of them
resembling the one pictured, and some with very different growth habits.
This common sulphur flower is one of the finest. Even in bud it is
brilliant, for the gold of its flowers, often touched with red, shows
before it is quite open. The soft sulphur yellow of the mature flowers
gradually changes to shades of orange, maroon and brown as they dry
rather than fade. They linger on their stems indefinitely and are fine
to mix with grasses and seed pods for a fall bouquet—they might even
trim an autumn hat!

    [Illustration: {uncaptioned}]




                            Buckwheat Family
                  Sand Begonia, _Rumex venosus_, PURSH


Flower parts are minute except the three inner sepals which rapidly
develop into conspicuous red to rose-colored wings or vanes about ½ inch
wide, attached to the seed. These vanes, with their seeds, develop into
compact clusters 2 inches or more in diameter. Leaves are oval or
oblong, fleshy and dark green, on short stout branches which are often
prostrate. Grows in plains. Blooms May-July.

This is just an ordinary dock closely related to the pest you dig from
your lawn, but a good example of a common wayside weed brightening the
bit of world in which it grows. That bit of world, for this particular
dock, is usually an ugly one, as it seems to choose the poorest soil it
can find, the cinders beside a railroad track—or the gravelly edge of a
country road. No one notices the small, insignificant flower, but its
hour of glory comes with the brilliant rose and red seed vanes that call
out gaily to every passerby. In the plains of western Colorado another
dock, _Rumex hymenosepalus_, is also spectacular growing to a height of
2 feet or more with a great column of rose-colored seed vanes.




                            Purslane Family
              Spring Beauty, _Claytonia lanceolata_, PURSH


    [Illustration: {uncaptioned}]

Flower is ½ inch across of 5 pale rose-colored petals, notched at the
end and with veins of darker shade. Sepals are only 2; plant is 6 inches
or less in height, with succulent stems and rather broad lance-shaped
leaves which rise almost as high as the loose raceme of 3 or more
flowers. Grows in rich soil montane and foothill zones. Blooms
immediately after snow melts which is late May to July, or much earlier
on warm slopes.

The plants of this species that grow in foothill locations often have
quite bright rosy color. They are great favorites, as their first blooms
hint that winter is nearly over and spring on the way. They have been
reported as early as January, and by mid-March they are often abundant
under scrub oaks on sunny foothill slopes. The east side of the Hogsback
near Golden is a good place to find early ones. The plant pictured above
has the pale color and general growth habit of those that grow high in
the montane zone. It often forms a carpet or ground cover of pale pink
bloom in the fields of glacier lilies. Another species, _Claytonia
megarhiza_, has a big root, to store food and moisture, and grows in the
alpine zone. We have found plants of it on the big flat summit of Pikes
Peak where other signs of spring are few.




                              Pink Family
                   Moss Campion, _Silene acaulis_, L.


    [Illustration: {uncaptioned}]

Flowers, ⅜ inch across, of 5 bright purplish-red petals, notched at the
end, spread from the top of a tubular calyx so that the whole flower
forms a tiny salver. Stems and leaves are so dwarfed and tightly grouped
as to give the appearance of a cushion of green moss 3 to 8 inches
across, studded with little reddish stars. Grows in alpine rocky areas
extending to peak summits. Blooms late June-early July.

This is one of the alpine flowers we share with all the alpine and
arctic lands of the Northern Hemisphere. High mountain ridges are its
home here, and if we travel north we keep finding it at progressively
lower elevations until it reaches the low barren lands of the arctic.
Always it is where winds are cold and climate is too rough for trees.
You might take it for a pad of green moss if it were not for its red
flowers, often in the form of a circlet near the plant’s edge. Close
examination shows a full-fledged plant, however, with leaves, stems and
a stout tap-root well buried in what soil there is below and around the
rock it presses against. Another member of the pink family that grows as
a mat against our timberline rocks is sandwort, _Arenaria sajanensis_.
Its flowers are white, and the plant less densely compacted. Related to
both of these alpine pinks are the numerous chickweeds of foothills and
mountains. They have low slender stems and their petals are white and
deeply notched at the end.




                            Buttercup Family
            Pasque Flower, _Pulsatilla ludoviciana_, HELLER


    [Illustration: {uncaptioned}]

Flowers, of 5 to 7 petal-like sepals, form a wide cup 1½ inches across,
white or pale lavender within, and much darker lavender to purple,
covered with silky hairs, on the outside. The numerous golden stamens
are prominent. The flower buds, quite furry at this stage, spring
directly from a buried root crown before the green leaves, divided into
several lobes, appear. Grows in foothills, especially on gentle north
slopes where extra snow has drifted. Blooms late March-April.

It goes also by the name of wind-flower, and often is called anemone.
Whatever name you choose, it is one of the best-loved flowers of the
Rockies. They are with us in March, going on into April, coming up
through late snows—keeping themselves warm with their furs about them.
The flowers start on short stems, but the whole plant grows quite large
and “leggy” as the season advances, and finally the fluffy seed plumes
offer their wares to every breeze. This same pasque flower is the state
flower of South Dakota. A northern species, growing in Glacier Park and
in Canada, _Pulsatilla occidentalis_, has larger flowers, of a creamy
color. Its cluster of seed plumes is large and dense enough to resemble
a dish mop.




                            Buttercup Family
                Globe Anemone, _Anemone globosa_, NUTT.


    [Illustration: {uncaptioned}]

Flower, ¾ inch in diameter, of 5 to 9 showy petal-like sepals, usually
deep red, occasionally yellow, forms a shallow cup around the numerous
stamens and a conspicuous group of pistils which, after the flower
fades, become a round thimble-shaped seed cluster. The pedicels, bearing
the solitary flowers at their tips, are several inches long and covered
with silky hairs. Plant is about 1 foot tall, with subdivided leaves
near the base and on the sparingly branched stems. Grows in partial
shade in montane zone. Blooms June-July.

This globe anemone, related to the better known pasque flower, is one of
the many less conspicuous plants that add to the charm of a flowery
hillside, yet reserve their more delicate beauty for those who take time
to prowl. This particular specimen was found in a glade filled with
columbines. We would probably not have seen it if we had not stopped to
try one more columbine picture! _Anemone canadensis_ is a somewhat
larger plant with pure white flowers, rather woody stems and deep green
foliage. It grows in shady places along foothill streams, but only where
conditions are to its liking. In these spots it forms rather dense
colonies.




                            Buttercup Family
            Nelson’s Larkspur, _Delphinium nelsonii_, GREENE


    [Illustration: {uncaptioned}]

Flowers, ½ inch or more wide, are formed of 5 showy, dark blue,
irregularly shaped sepals, enclosing at their base 4 much smaller petals
of lighter color. The uppermost sepal extends backward as a slender spur
½ inch or more in length. About a dozen flowers on slender pedicels
group around a central erect stem to form a loose raceme which often
nods slightly at the top. Plant is 10 to 15 inches tall and bears rather
few leaves each sub-divided into linear segments. Grows in foothills
zone. Blooms late April to early June.

This small larkspur of the early spring looks much like the single
larkspur of an old-fashioned garden. Its favorite location is near the
base of a clump of scrub oak where a little snow has drifted in the
winter giving that spot a bit of extra water. The intense blue of these
flowers contrasts well with the leather brown color of last season’s oak
leaves. When spring is farther advanced other taller larkspurs, such as
_Delphinium geyeri_, called poison-weed by the stockmen, make a more
spectacular showing on low foothills and plains. All of the larkspurs
contain an alkaloid poison which is deadly to cattle and somewhat
dangerous to other stock.




                            Buttercup Family
               Snow Buttercup, _Ranunculus adoneus_, GRAY


    [Illustration: {uncaptioned}]

Flowers are an inch across, formed of several (3 to 15) broad,
overlapping golden petals having the glossy sheen of butter. The sparse
leaves are divided into linear lobes. These and the succulent stems grow
a few inches tall, breaking out of frosty soil with flower bud ready to
open. Grows on alpine and sub-alpine slopes near snow banks. Blooms when
snow melts, usually June to early July.

The hardiness of the snow buttercup is its outstanding characteristic.
It comes up through the snow because in the high altitude in which it
lives its time for fruition is short. It pushes a stout knuckle of stem
through the snow crust, attracting the sun’s heat by the dark color of
its stem, then the knuckle straightens, lifting the already formed bud
into an erect position. The bud opens rapidly and proceeds to spread out
in the hole caused by melting. Of the many glossy members of the
buttercup family, there are few of so rich a yellow, or which give such
an appearance of being all flower with inconsiderable leaf and stem.




                            Buttercup Family
                 Globeflower, _Trollius laxus_, SALISB.


    [Illustration: {uncaptioned}]

Flower is 1¼ inches across of 5 to 10 (or more) pale cream petal-like
sepals, with numerous yellow stamens and several pistils in the center.
Numerous petals, so dwarfed as hardly to be noticed, surround the base
of the stamens. Plants, 8 to 15 inches tall, often grow in groups and
bear several flowers, each on its own slender stem. Leaves are dark
green and deeply cut into 5 or more spreading lobes (palmate). Grows in
moist rich soil in sub-alpine and alpine zones. Blooms late May-July.

When the snowbanks melt in the alpine country, hundreds of temporary
runlets carry the snow water to timberline lakes and to permanent
streams. In the wet soil along these runlets and near these lakes,
globeflower is one of the common and very good looking plants. Both its
foliage and its flowers are graceful and charming. Associated with it is
usually marsh marigold, _Caltha rotundifolia_, which is also a member of
the buttercup family. Our Colorado marsh marigold is not gold at all,
but white—even a bluish-white. It grows with its feet right in the
water. Its leaves are entire and are all at the base of the sturdy low
plant. Its flowers are as large or slightly larger than those of
globeflower. It makes an effective companion for its more dainty
relative.




                            Buttercup Family
                 Columbine, _Aquilegia coerulea_, JAMES


    [Illustration: {uncaptioned}]

The flower is formed of 5 sepals and 5 petals, alternately arranged and
all of them showy. The sepals are deep blue or sometimes quite pale,
forming a wide saucer-like star 3 inches across; the petals form a white
inner cup 1¾ inches across, and stretch back between the sepals as
hollow, slender 2-inch spurs. Plants are 2 feet or more high of several
delicate stems, usually carrying at their tops numerous flowers. The
deeply cut leaves are mainly concentrated at the plant base. Grows in
rich soil in montane zone, but extends into foothills and up to
timberline. Blooms June-July.

Colorado’s queenly state flower speaks for itself much more eloquently
than humans can speak for it. No portrait can do it justice. We have
found it in the very glade near Palmer Lake where James first saw it and
named it _coerulea_ for its celestial blue. We have found it in
countless aspen groves of the montane zone and finally on rocky scree
near timberline (a more compact plant there—with flowers sometimes white
or of a rosy hue). Always there is the thrill of real discovery—a new
realization of its beauty. A less common and even more exciting find is
the dwarf columbine, _Aquilegia saximontana_, that grows between rocks
above timberline.




                              Poppy Family
              Prickly Poppy, _Argemone intermedia_, SWEET


    [Illustration: {uncaptioned}]

Flower, 3 inches or more across, is formed of 6 brilliant white,
paper-like petals, surrounding numerous golden stamens with, at the very
center, a dark or even black stigma. Blossoms, in loose clusters opening
over a long period, crowd each other slightly at the tops of the
branching stems. Plant is 2 to 5 feet tall, with gray-green leaves
divided into lobes, and with yellowish spines along the stems and leaf
ribs. Grows in plains, foothills and lower montane zones. Blooms
May-September.

These big coarse plants, which may be seen in small groups along our
roads at culvert ends and in neglected fence rows, could be taken for
some sort of thistle if it were not for the amazing flowers which they
display in successive crops throughout the whole summer. The blossoms
look like big circles of white crepe paper with a center of spun gold.
As the season advances, the plants get ragged, but even in September a
few fresh flowers will appear. Some resemblance can be seen between
these blossoms and the Oriental poppies of our gardens, but only by
study of their botanical structure can we find why they are put in the
same family with golden smoke, _Corydalis aurea_, of our foothills, and
the bleeding-heart of old-fashioned gardens.




                             Mustard Family
                  Wallflower, _Erysimum asperum_, DC.


    [Illustration: {uncaptioned}]

Flowers, ½ inch in diameter, are formed of 4 petals arranged like a
Maltese cross, yellow to orange in color. They are clustered into a
round terminal head, the lower flowers of which open first so that
usually tubular seed pods (siliques) have formed near the base by the
time the top of the cluster is in bloom. Plants are 8 inches or more
high, of several stems from one root crown. Grows in foothills,
extending down to plains and up through montane zone. Blooms May-July.

The mustards are legion. Fields of them add a yellow note to many
western hillsides. They range from weedy poor relations, like shepherd’s
purse, to tall, showy spikes of prince’s plume, _Stanleya apinnata_.
Wallflower—despite its name suggesting a colorless personality—is one of
the handsome children of the family. Its flowers, larger than most
mustards, range in color from pale yellow, through orange, to rich
bronze shades. By no means all of the mustards are yellow. The flowers
of many of them are white, some, like the cardamine that grows in
abundance along sub-alpine water runs, being a very showy, brilliant
white.




                            Saxifrage Family
           Snowball Saxifrage, _Saxifraga rhomboidea_, GREENE


    [Illustration: {uncaptioned}]

Individual flowers are ¼ inch or less across, each with 5 white petals,
and are grouped in a compact, round-topped head about 1 inch in diameter
which forms the top of a naked stem (scape). This scape rises to a
height of 8 inches, or sometimes much less, from the center of a flat
circle of oblong, leathery leaves. As the blossoms age, the flower
cluster becomes loose and sprangly. Grows on moist slopes in sub-alpine
and montane zones. Blooms May-July.

Saxifrage is another large family of quite varied sorts. Gooseberries
and mock orange come within its membership. The numerous species of alum
root, _Heuchera_, are also included, as are many little alpine and
sub-alpine plants that grow out of rock crevices in our high mountains.
Purple saxifrage, _Saxifraga jamesii_, with quite large red-purple
flowers, and dotted saxifrage, _Saxifraga austromontana_, with tiny
white flowers covered with pale dots, are among the best. All of these
seem able to thrive on only a teaspoonful of soil in a rock crack, if
only there is local moisture. The structural features that bring all
these plants within one family are not obvious. The leaves of many of
them are similar to the leaves of a gooseberry bush, though in some this
resemblance is remote, and in others entirely absent.




                             Orpine Family
                Queen’s Crown, _Sedum rhodanthum_, GRAY


    [Illustration: {uncaptioned}]

Individual flowers, ¼ inch across, are formed of 4 or 5 bright rose
petals; numerous flowers being congested in a round head an inch or more
in diameter terminating a leafy shoot, several of which rise from a
woody root crown. Plant is 6 to 10 inches high, with narrow, gray-green,
fleshy leaves crowded along the succulent stems. Grows in wet places
alpine and sub-alpine zones. Blooms June-August.

Along the cold, mountain stream trickling out from Lake Isabelle, or
near any similar alpine lake or tarn, grows the _Sedum_, named queen’s
crown for the rosy-pink crowns of blossoms. These plants like to have
their feet in the water and often help to make the hillocky mounds on
the lake’s edge. Nearby and tolerating drier ground, is the king’s
crown, _Sedum integrifolium_, with its flatter head of deep maroon
flowers resembling the old-fashioned Bohemian garnet jewelry. The stems
and leaves of these sedums color brilliantly with the first frosts and
add richness to the Persian carpets of timberline in late August and
early September.




                              Rose Family
              Bush Cinquefoil, _Potentilla fruticosa_, L.


    [Illustration: {uncaptioned}]

Flowers are an inch in diameter, of 5 broad, golden petals surrounding
20 or more stamens. Groups of several flowers are borne at the ends of
the numerous short branches. Plant is a dense shrub about 3 to 4 feet
high with many dark, woody, freely-branching stems. Leaves are pinnate,
with usually 5 or 7 narrow linear leaflets. Grows in moist parts of the
montane zone, also in the upper foothills and the lower sub-alpine
zones. Blooms continuously May to September.

This thornless yellow rose is one of the most widespread and most
ornamental shrubs of mountain areas. Individual clumps are rarely fully
covered with bloom at any one time, tending rather to bring out a few
fresh flowers each day of the season so that all summer long there are
buds, fresh blossoms, groups of faded petals, and small, dry, fuzzy
seeds (achenes) distributed over the plant. Other species of
_Potentilla_ grow also in our mountains. They are much smaller and most
of them herb-like, but the resemblance to a yellow single rose, and the
absence of thorns are common to them all. We have many wild roses in
this same family, of the genus _Rosa_, that have plenty of thorns and
closely resemble the red single roses of the garden.




                               Pea Family
           Prairie Pea, _Lathyrus stipulaceus_, B. AND ST. J.


    [Illustration: {uncaptioned}]

Flowers, more than ½ inch across, are shaped like a cultivated sweet
pea, with very showy red banner and paler lateral petals and keel.
Plants, about 6 inches high, grow in irregular mats. The leaves are
pinnate, formed by about 4 pairs of narrow linear leaflets. These and
the stems are gray-green and, in most plains specimens, covered with
rather silky down. Grows in sandy soil on plains. Blooms May-June.

This, and the quite different looking plants shown on the next three
pages, give but a small sample of the pea family, which is one of the
largest and most important of the plant groups. More than 150 species in
this one family are native to Colorado, and additional ones have been
introduced for ornament or food. They take every form and size from the
little flat mats of deer clover, shown on the opposite page, to the rank
growing clumps of sweet clover that spread themselves along our roads.
Beans and alfalfa as well as sweet peas, lupines and even locust trees,
all belong to this big family.




                               Pea Family
                 Deer Clover, _Trifolium nanum_, TORR.


    [Illustration: {uncaptioned}]

Individual flowers, pink-lavender to purple, formed along a keel, like
those of the cultivated clovers, about ½ inch long and rather slender,
grow singly or in twos or threes on short pedicels rising directly from
the root crown. The plant is a dense mat, often a foot or more across,
covered with small 3-foliate leaves. Grows on rocky flats or slopes in
alpine zone. Blooms June-July.

For many, acquainted only with the cultivated clovers of lawn and
meadow, it is a pleasure to know that the high pastures grazed by deer
and elk have clovers as well. At least three species are familiar to
observing travelers along Trail Ridge, or up Mt. Evans, or along any
road that crosses the enchanted land where trees stop and dwarfed plant
life takes over. The deer clover pictured here likes rocky places. Its
flowers are packed close together, but not clustered in heads as are
those of its alpine neighbor, _Trifolium dasyphyllum_, which closely
resembles the white clover of our lawns, though with touches on its
petals of red-brown. In the high places, extending down through the
sub-alpine zone there is also a bright red clover, _Trifolium parryi_,
smaller but otherwise much like the cultivated red clover.




                               Pea Family
              Lambert’s Loco, _Oxytropis lambertii_, PURSH


    [Illustration: {uncaptioned}]

Individual flowers, about ½ inch wide, are formed of 5 dissimilar
petals, usually magenta red, sometimes other shades from rose to purple.
The banner bends back slightly and carries markings of lighter color
near its base; the 2 lateral petals are plain and angle forward; the 2
lower petals form a narrow keel. Numerous flowers, attached at the calyx
base along the upper third of a naked stem, form a showy spike 10 inches
or more tall, several of which rise from one root crown. Leaves,
pinnate, with numerous green leaflets, rise also from the root crown and
are about half the height of the flower spikes. Grows in foothills and
higher parts of plains zone. Blooms May-July.

The many members of the pea family going by the names of loco, vetch,
milk vetch, etc., are usually considered crass weeds and are in
disrepute because some of them are poisonous to stock. They often grow
in soil containing traces of selenium, and are doubly harmful in that
case. Where other browze is good, animals usually leave the toxic ones
alone, except the occasional horse that becomes “an addict” and is
“locoed.” In spite of these obnoxious qualities, there are few plants
that give more bright and decorative touches to the plains.




                               Pea Family
           Golden Banner, _Thermopsis divaricarpa_, A. NELS.


    [Illustration: {uncaptioned}]

The individual flowers are about ¾ inch across, each formed of 5
dissimilar golden petals. The top petal is an upright banner, with a
wing petal on each side and in the center the 2 keel petals folded
together. A dozen or more flowers are attached by short pedicels to the
upper part of the stem, forming a loose raceme. Plants, of one or
several erect leafy stems from a root crown, are 1-2 feet tall. Grows in
foothills and montane zones. Blooms April-July.

Several closely allied species share the name of golden banner, and
among them cover a very wide range in all parts of Colorado from the
plains well into the mountains. They spread both by seeds and by
root-runners resulting in quite large colonies. They seem to be
unpalatable to livestock so, in spite of their attractive looking
leaves, they stay fresh while other plants around them look browzed.
Everywhere they are gay and decorative. A bright field of them near the
Platte River, bowing to the wind, banks of them in open glades of the
Greenhorn Mountains, and pale yellow clumps along the trail to Lulu
City, are prized flower memories.




                              Loasa Family
                 Stickweed, _Mentzelia nuda_, T. AND G.


    [Illustration: {uncaptioned}]

Flowers, about 2 inches wide, are formed of 10 narrow, creamy, petals
which spread wide and surround a radiating cluster of 100 or more pale
stamens as long as the petals. Plant is 2 to 4 feet high of white shiny
stems branching freely from one main stem, and rather sparsely covered
with deeply indented, light green leaves of a peculiar rough texture.
Grows on plains and low foothills. Blooms July-August.

The leaves of this plant are covered with minute barbed hairs which
cling to cloth so firmly that a spray of several flowers placed upon a
coat lapel will stay almost as dependably as if fastened with a pin.
They have the feel of fine-grained sandpaper. The flowers are very
responsive to light conditions. All through the morning and well into
the afternoon they are tightly closed, then about four o’clock, or a
half hour earlier if clouds reduce the light, they spread into full
bloom. This opening proceeds so rapidly that the movement of the petals
is quite easily seen. In a period of twenty minutes or less a colony of
the plants will change its whole appearance from inconspicuous weeds to
a gorgeous display of big pale stars. A related species, _Mentzelia
decapetala_, has even larger flowers of deeper cream color. It waits
until after sundown to open.




                             Cactus Family
       Strawberry Cactus, _Echinocereus triglochidiatus_, ENGELM.


    [Illustration: {uncaptioned}]

Flowers are brilliant scarlet, 2½ inches across, with a conspicuous
group of green stigmas in the center. Plant is a single, erect,
cylindrical, dark-green joint or stem about 5 inches high, several to
many of which often group closely together forming a mound. The stems
are strongly ridged and carry sharp spines in clusters. Grows in rocky
or gravelly soil on plains and into foothills, southwestern Colorado.
Blooms May.

This is related to some larger _cacti_ that grow in Arizona, and there
get the name of hedgehog. The name pincushion is broadly used for all
the small round _cacti_ of our area even though they are not too closely
related to each other. The bright, strawberry-red flowers of the plant
shown above quite set it apart from the pincushions of eastern Colorado
plains. Among these are hen-and-chickens cactus, _Echinocereus
vividiflorus_, with small, greenish-yellow flowers, also, spiny stars,
_Coryphantha vivipara_, a round little cactus with shiny purple flowers.
These plants are so like the prairie sod in color as to defy search when
not in bloom. Ball cactus, _Pediocactus simpsonii_, of foothills and
montane zones, is quite a perfect globe in shape, 3 to 6 inches in
diameter, and has small pink flowers closely grouped at the top of the
globe.




                             Cactus Family
      Grizzly Bear Cactus, _Opuntia trichophora_, BRITTON AND ROSE


    [Illustration: {uncaptioned}]

Flowers are 3 inches or more across, usually light-yellow with fine
sheen, several of them erupting from the edge of a flat, oval joint.
Plant spreads over a circular area, about 2 feet in diameter, and is
made up of numerous connected flat joints, of light-green color, all
heavily armored with pale, sharp spines, some of which, in old plants,
may be flexible and hair-like. Grows on clay soil in foothills and
plains of middle and western Colorado. Blooms June-early July.

Several species of Opuntia closely resemble each other. Some of them,
including a few found in Colorado, bear soft, juicy fruits which are
quite good eating when the prickles on the skins are removed, so all of
them are called prickly pear. The one shown above grows freely on the
high grassy flats of the San Luis Valley. It bears dry, hard fruits, as
do most of our Colorado species. The prickly pears, like all the other
cacti, accumulate moisture, when they get a chance, in the soft pulp of
their round or jointed stems. Then, over periods of drought, this
moisture is used to produce flowers, to mature seeds and to keep the
plant alive. The whole plant shrinks visibly if the times between drinks
are long. But for the defensive armor of their spines, few of them would
survive, because in a thirsty land every hungry cow is looking for
moisture too.




                        Evening Primrose Family
         Yellow Evening Primrose, _Oenothera brachycarpa_, GRAY


    [Illustration: {uncaptioned}]

Flowers are cadmium-yellow, fading old-rose, 2½ inches across, of 4 wide
petals. The 4 narrow sepals bend back and at their base merge into a
hollow tubular stem. The style branches at its tip into 4 conspicuous
slender stigmas. Plant has little or no main stem; leaves are
dark-green, strap-shaped, 3 inches long. Grows in foothills, but only
where soil is somewhat marly. Blooms May-June.

Look for this one of our numerous evening-primroses about Memorial Day.
Soil formed from the disintegration of Niobrara shale such as we find
along the Hogsback near Denver, or along the Boulder-Lyons road, is its
preference. The plants are rather ragged, but the flowers draw all our
attention to their soft, clear yellow as they spread open in the
sunshine. They last but a day—fading into soft rosy colors. The white
members of this family are much better known. Several such species
common on the plains are so responsive to early summer rain that within
days after a good shower all our roadsides and even vacant lots will be
gay with their short-lived beauty.




                        Evening Primrose Family
                Fireweed, _Epilobium angustifolium_, L.


    [Illustration: {uncaptioned}]

Individual flowers, 1 inch across, are formed of 4 wide-spreading,
magenta petals, and are attached by longish pedicels to a central stem,
so that the whole flower cluster (inflorescence) is a loose raceme
forming the top foot or more of a tall leafy shoot, several of which
rise from a woody root crown. Leaves are narrow, 2 inches or more in
length. The entire plant is often 4 feet or more tall. Grows in sunny
openings in montane zone. Blooms June-August.

Webster’s Dictionary describes fireweed as “any of several weeds,
troublesome in clearings or burned districts.” To use “troublesome” in
connection with this great “willow-herb” of the Rockies seems most
unkind. We are grateful to have it rush into devastated areas to cover
scars with its bright pink to magenta blossoms. The whole plant reddens
as it ages. The flower matures into a long thin pod which splits and
curls releasing feathery seed carriers. A less common low growing
species with larger flowers and broader leaves, _Epilobium latifolium_,
also grows in the area. It is a real find. A few grow not far below
Loveland Pass.




                              Heath Family
               Pipsissewa, _Chimaphila umbellata_, NUTT.


    [Illustration: {uncaptioned}]

Flower, ½ inch across, formed of 5 rose-pink petals that bend back and
surround, at the center, a conspicuous bright green ovary which is
tipped with a disc-like stigma. The 10 prominent stamens, spreading from
near the base of the ovary, look like short claws. Plant is 8-12 inches
tall, bearing a cluster of several flowers at its top. Leaves are shiny
and evergreen with saw-toothed edges, arranged in whorls along the woody
stems, but most numerous at the base of the plant. Grows in moist acid
soil under pine or spruce trees in montane zone. Blooms late
July-August.

The members of the heath family like shade, acid soil and moisture.
These conditions they find in the woods of the Northwest, where a great
variety of them, including rhododendrons and azaleas, grow in abundance.
Colorado has its share of the smaller heaths for those who look for them
in shady spots and along mossy trails near mountain streams. The trail
to Calypso Falls in Rocky Mountain National Park is good hunting, not
only for pipsissewa, but for the pyrolas and for the tiny white
wood-nymph, _Moneses uniflora_, all of them heaths. Kinnikinnick,
_Arctostaphylos uva-ursi_, is a heath of prostrate growth habit quite
common on mountain slopes. Bright red berries remain among its evergreen
leaves until Christmas.




                            Primrose Family
                 Brook Primrose, _Primula parryi_, GRAY


    [Illustration: {uncaptioned}]

Individual flowers, almost ½ inch across, are formed of 5 brilliant,
crimson, spreading corolla lobes which join at their base into a narrow
tube; dark shadings and yellow markings at the throat of the tube give
the effect of a round eye. A dozen or more flowers, each on a nodding
pedicel, are clustered at the top of a stout dark stem which rises from
a whorl of deep-green, broad, lance-shaped leaves. Plant is about 10 to
20 inches tall. Grows in sub-alpine zone or slightly higher. Blooms
June-early July.

This spectacular primrose grows at the edge of cold streams, or often on
rocky-mossy hillocks right in mid-stream. One never forgets the picture
of their beauty—the flower clusters so rich in color, the alpine
background, the mat of moss and deep green leaves. Too bad for such a
plant to spoil any part of it with a most disagreeable fragrance, yet
that does remove any temptation to take them home. On the higher
tundras, a charming find is the tiny fairy primrose, _Primula
angustifolia_, similar in color, though not so vivid. A single
short-stemmed flower is usually all that this plant carries.




                            Primrose Family
             Shooting Star, _Dodecatheon radicatum_, GREENE


    [Illustration: {uncaptioned}]

Individual flowers, ¾ inch across, are formed of 5 crimson, rather
narrow, petals or corolla lobes which flare outward and backward, but
unite at their base into a short tube. From this tube 5 conspicuous
anthers, over ¼ inch long, grouped together like a sharp straight beak,
protrude forward. Ten or more flowers, each on a slender pedicel, nod in
a cluster at the top of a stout scape which rises 10 to 15 inches high
from a basal mat of dark-green, oblong leaves. Grows along streams and
in wet meadows, in montane and sub-alpine zones. Blooms June-early July.

Both the coloring and the shape of this little flower are fancy indeed.
It is small wonder that such names as shooting-star and bird-bill have
been given it. The crimson of its petals contrasts strongly with its
conspicuous almost black “bill,” and between these colors is a little
circlet of white, often shaded with yellow markings. A whole meadow of
such flowers is a sight well worth a trip to South Park, or to other of
our high meadow areas, where shooting-stars can be found in profusion.
In blooming season they follow the wild iris and, in turn, they are
followed by the low, red lousewort, _Pedicularis crenulata_, all of
which can in favorable seasons give fine mass color effects.




                             Gentian Family
             Fringed Gentian, _Gentiana elegans_, A. NELS.


    [Illustration: {uncaptioned}]

Flowers are 2 to 3 inches long, of 4 deep purple-blue petals, fitted
together to form a square column for over half their length, then, in
sunlight, flaring outward to exhibit fringed tops and upper edges. Each
flower is at the end of a stem which bears several pairs of oblong,
opposite leaves. Plants are about 12 inches high of several erect stems
branching from near the base. Grows in sub-alpine wet meadows. Blooms
August-September.

The lush hay meadows of Colorado’s upland parks are bright through the
summer with a succession of flowers. Late in the season come the
gentians. There are several species of these (we have counted a dozen on
a single trip), some of them quite uninteresting, weedy plants. The
queen of them is the fringed gentian, growing in abundance along the
edge of these high hay meadows, and even persisting in the stubble after
haying is past. A few of them last into late September. The flowers
close up under cloudy skies, but to find masses of them full-open on a
sunny day, when they display their fringed petals and large golden
stamens, is a heart-warming experience to be treasured for flowerless
days ahead.




                            Milkweed Family
                 Milkweed, _Asclepias speciosa_, TORR.


    [Illustration: {uncaptioned}]

Individual flower is a rosy, 5-point, star about ⅜ inch across, at the
center of which is a group of 5 small appendages curving inward and
forming a crown around the style and stamens. Numerous flowers cluster
together into a ball about 3 inches in diameter. Plants are about 3 feet
tall with thick broad leaves, the flower clusters borne at the top of
the stem and in axils of upper leaves. Grows on plains, especially along
ditch banks. Blooms June-July.

The common weeds are too often taken for granted and not appraised for
their real beauty. This milkweed is in such a group—a coarse-growing
plant along country roads, often dust covered, yet with flowers of fine
delicate color and real charm whether we examine them singly or fix our
attention on the compact cluster in which they grow. As autumn comes the
dry leaves do not drop, but cling to the stem, rattling in the wind. The
rough seed pods, often four inches long, turn a rich brown, and finally
split open revealing a filling of lustrous, silky, down from which is
gradually released the seeds—brown-clad paratroopers with the most
airy-fairy parachutes in the world.




                          Morning-glory Family
            Bush Morning-glory, _Ipomoea leptophylla_, TORR.


    [Illustration: {uncaptioned}]

The flowers, shaped like pink trumpets with maroon striations, 3 inches
long and 2 inches across the mouth, are scattered freely along the outer
third of the stout yellowish stems which form a thick bush 2 feet or
more high. New buds coming out each day keep the plant in bloom for the
morning hours of several weeks. Leaves are narrow and linear, 2 inches
long; the root is large and spongy. Grows in sandy soil on plains.
Blooms July.

This morning-glory is no clinging vine, even though its flowers—like
those of its cultivated relative on the back yard fence—do open only in
the coolness of dawn and wither in the heat of noon. For all the
sturdiness of individual plants, with their roots going “clear to
China,” they do not seem to multiply rapidly and colonies of them may be
miles apart. There are some fine bushes on the sandy hills along the
Denver-Parker road, but the colony is becoming smaller rather than
expanding. The common bindweed, _Convolvulus arvenis_, is a member of
this same family. Its ability to spread rapidly along roads and into
cultivated fields makes it a serious pest.




                            Waterleaf Family
                Purple Fringe, _Phacelia sericea_, GRAY


    [Illustration: {uncaptioned}]

Numerous purple flowers, each ¼ inch in diameter, crowd at and near the
top of an erect hairy stem, making a cylindrical flower spike 3 inches
or more in length. The 5 stamens of each flower are tipped with bright
golden anthers and stick out farther than the petals, giving the effect
of gold-headed pins radiating from a purple cushion. Plant is 6 to 12
inches tall of several leafy stems from a woody crown, the leaves
divided into numerous narrow lobes. Grows in rather dry soil, montane to
sub-alpine zones. Blooms May-July.

Many other species of _Phacelia_ live in desert places where we have
learned to know and admire them, but our first acquaintance—and last
love—is this purple fringe of the montane zone. Its color is deeper,
more velvety, and the pollen of its anthers brighter gold than most of
its desert brethren can boast. It keeps, however, considerable tolerance
for dry places, so that fresh road-fills are gay with it. The
mountaineer who views his flowers only from a car has no excuse for not
knowing this one.




                             Borage Family
        Alpine Forget-me-not, _Eritrichium elongatum_, JOHNSTON


    [Illustration: {uncaptioned}]

Flowers, ⅜ inch in diameter, are formed of deep-blue (occasionally
white) petals, spreading into a little flat disc and joining at their
base into a short tube. Minute golden crests in the throat of this
corolla tube, often bordered by white, give the effect of a central eye.
Plant is formed of a tough woody root crown bearing several very short
leafy shoots with flower clusters at the top. Entire plant is compact,
covered with short silky hairs, and rarely 3 inches high. Grows on flat
spots between rocks in alpine zone extending clear to peak summits.
Blooms late June-early July.

The plant “association” pictured above is such as we find on Trail
Ridge. It has bright lichen, sedum, polemonium and alpine
forget-me-not—the kind of miniature garden that makes high altitude
flower hunting so much fun. The woody base of the forget-me-not is built
to stand the cold of long winters. The flowers—tiny and delicate for so
rugged a habitat—are of heaven’s own blue. Their exquisite perfume is
elusive. Only once have we found them in such abundance that the
fragrance called out to tell us where they were hiding. Their range is
wide, however, and in the short blossoming season there is a good chance
of finding a few on the slopes of any of our high peaks.




                              Phlox Family
                Sky Pilot, _Polemonium viscosum_, NUTT.


    [Illustration: {uncaptioned}]

Numerous violet-blue flowers, each about ½ inch across, of 5 rounded
corolla lobes joining in a funnel-like tube, are clustered into a head
about 2½ inches in diameter, which nods slightly on its erect stem.
Plants are about 8 inches high, with numerous bright-green, pinnate
leaves cut into many narrow leaflets. The leaves may be erect or may
interweave somewhat at the base of a close group of several plants.
Grows in rocky places, alpine zone. Blooms late June-early July.

The sky pilot, growing among rocks up where the sky seems very near,
reflects its blue and so is supposed to direct our thoughts upward. This
same feeling is embodied in the name of another species of _Polemonium_,
Jacobs ladder, _Polemonium pulcherrimum_, the staggered leaves of which
may represent the steps by which we climb. Sky pilot seems very much
affected by the particular season. In a dry summer, it is straggly and
manages to produce only a few blooms of faded blue. In a good year,
large clumps of sturdy erect plants make patches of deep color, accented
by their golden stamens. The leaves have a strong, offensive odor, but
the flowers are honey sweet.




                              Phlox Family
               Scarlet Gilia, _Gilia aggregata_, SPRENG.


    [Illustration: {uncaptioned}]

Individual flower, 1½ inches long, is formed of a slender trumpet-like,
bright-scarlet (sometimes coral pink) corolla flaring at the mouth into
5 narrow lobes. Numerous flowers attached by short pedicels, are carried
in small groups along one side of the green stem. Plant is about 18-24
inches tall, usually of one main stem, with sometimes a few branches.
Leaves are deeply cut into thin linear subdivisions, usually curved.
Grows in plains and foothills zones. Blooms June-August.

In many otherwise barren areas, the red gilia or sky rocket plant
spreads its blaze of color in large patches or hangs, a single wand of
bloom, over the edge of the trail. It keeps blooming through the summer,
a few stragglers holding on till Labor Day. In early September we have
found them in the Wet Mountain Valley brightening the brown of the
autumn grasses. A white species, _Gilia attenuata_, tends to grow at
lower elevations—the red higher in the foothills. The pale pink and
coral plants are probably hybrids.




                             Figwort Family
             Indian Paintbrush, _Castilleja integra_, GRAY


    [Illustration: {uncaptioned}]

The true flowers are slender, two-lipped tubes of pale or greenish color
about 1 inch long. They are surrounded and often completely hidden by
the conspicuous, brick-red, modified leaves (bracts) which form a
flower-like cluster at the upper ends of the stems. The bract colors in
this species vary considerably through several shades of red. Plant is
8-15 inches tall composed of several leafy stems, very tough and woody
at their lower ends, rising from a woody root crown. Grows in foothills
and higher plains, extending upward through montane zone. Blooms
June-July.

In the early summer, this spectacular plant may be seen in the prairie
stretches along the highway between Denver and Colorado Springs—or a bit
later in the season—literally carpeting the drier areas of South Park.
In higher altitudes, particularly in the well-watered vales of Engelmann
Spruce, there are other species with bracts of brilliant shades of rose
and maroon. In those same high gardens and on above timberline there is
a yellow paintbrush. The fortunate flower hunter may even be rewarded by
a yellow one tipped with red—or red edged with yellow.




                             Figwort Family
               Penstemon, _Penstemon unilateralis_, RYDB.


    [Illustration: {uncaptioned}]

Individual flower is about ½ inch wide and somewhat longer, formed of a
bell-shaped, lavender-blue corolla which flares at its mouth into 5
lobes separated into two groups. Numerous flowers, in groups of 3 or
more, are closely arranged along one side of the top half of each stem,
several stems rising from a root crown. Plant is 2 feet or more tall,
with narrow tapering leaves, opposite each other in pairs. Grows in
foothills and montane zones. Blooms late June-July.

This is but one of twenty or more species of Penstemon found in
Colorado. Some, such as _Penstemon angustifolius_, with its azure blue
flowers, grow on the plains. A few are dwarf species of the sub-alpine
zone such as _Penstemon harbourii_. Every zone and every section has its
quota, and they range in color through all shades of lavender, blue,
purple, and even red. In details of flower structure, as well as in
size, they vary considerably. All of them, however, have a tubular
corolla of some shape, terminating in five lobes, divided into two
groups, giving them a two-lipped appearance. From this their
relationship to garden snapdragons is apparent. In the penstemons, also,
the topmost of their five stamens is sterile and often tipped with a
little brush of hairs. This gives them the name of beardstongue.




                            Composite Family
                Gaillardia, _Gaillardia aristata_, PURSH


    [Illustration: {uncaptioned}]

Flower head, 3 inches or more across, is formed of a central red disk
made up of many minute tubular flowers (florets), surrounded by an outer
circle of long flat golden rays cleft at tips into 3 teeth. Plants are 2
feet or more high of several rough stems usually erect, but sometimes
contorted. The dark green leaves are lance-shaped and rough. Grows in
foothills. Blooms June-July.

Do you have one just like this in your garden? Cultivation has changed
the gaillardia less than it has most native plants. It was born a
handsome, showy flower. There is charm in its notched rays and in the
way the red of the central disk flowers runs outward into the gold of
the rays, as though the painter had been careless with his brush and
lavish with his colors. It grows far beyond the limits of Colorado. In
the rough breaks of the Montana hills several separate plants will
spread out and interweave as a colorful mass, giving it there the name
“blanket-flower.”




                            Composite Family
           Rabbit Brush, _Chrysothamnus nauseosus_, H. AND C.


    [Illustration: {uncaptioned}]

Individual flower heads are about ¼ inch across and double that in
length, each formed of a dozen or more tubular bright gold florets
closely compressed at their bases into a green involucre. Numerous such
heads are clustered loosely together into round-topped groups (cymes) at
the ends of stems and branches. Plant is a wide-branching, woody shrub
2-4 feet high with small, green-gray, linear leaves. Grows on dry plains
and lower foothills, especially common in western Colorado. Blooms
September-October.

Most of the better known composites have spreading rays—each of which is
really a flower, though usually sterile—surrounding a disc of less
conspicuous tubular flowers, these latter being normally the fertile
ones. Sunflowers are familiar examples. Throughout some genera of this
great family, and in various species of additional genera, the rays are
totally absent. Rabbit brush is one of the composites whose flower heads
have no rays. They are showy only because so many of them cluster
together, and because each small flower contributes a speck of bright
gold. They are distinctly plants of desert lands, and in the fall season
each big clump is a perfect mound of color. As winter nears, the color
pales and fades, though flowers hang on a long time. Rabbit brush is not
a sagebrush, even though both grow on the same dry plains and both are
members of the composite family.




                            Composite Family
               Easter Daisy, _Townsendia sericea_, HOOK.


    [Illustration: {uncaptioned}]

Flower heads, 2 inches across, are formed of about 30 white rays,
slightly striated and indented at the tips, surrounding a disc, about ¾
inch in diameter, of numerous tubular gold-colored florets. Plant is
about 3 inches high and carries one or several flower heads right on the
top of a spreading tough root crown from which also rise numerous,
narrow, linear leaves about 2-3 inches long. Grows on grassy plains, and
foothills. Blooms April-May.

These are among the very earliest of the plains flowers. Their typical
occurrence is as isolated plants, one here and one there between grass
turfs in areas of rather tight prairie sod. They are so low and compact
that they are not easy to find, even though their beauty well justifies
the search. Spring has come when Easter daisies are out, even though the
plains are still clad in winter gray with only a faint suggestion that
in time the range will be green. Several other members of this daisylike
genus are found in the foothills and plains. One of the commoner of
these, _Townsendia eximia_, is easily distinguished by its short
spreading branches which carry a few leaves.




                            Composite Family
             Showy Fleabane, _Erigeron speciosus_, C. FONG


    [Illustration: {uncaptioned}]

Flower head, 1½ inches across, is composed of about 200 narrow rays of
brilliant lavender color, surrounding a button-like center ½ inch in
diameter, of numerous, bright-gold, tubular florets packed closely
together. Plant is 1½ to 3 feet high, freely branching, with numerous
flower heads; leaves oblong or oval 2-3 inches long. Grows in shady
places, rich moist soil, montane and sub-alpine zones. Blooms late
July-September.

As the season advances, these aster-like flowers become the most
conspicuous color notes in our high-altitude aspen groves. They come
after early flowers are gone and bloom with a profusion unknown to most
shade-loving plants. Before they too are gone a leaf here and there on
the geranium plants in these same places will have turned bright red; on
the ground, ivory colored puff-balls will be ready to discharge their
clouds of brown spores, and the very first of the aspen leaves will have
turned yellow and be drifting down. Showy fleabanes may linger to catch
the first fall snows. Another of the many members of this genus,
_Erigeron trifidus_, grows on the plains and brings out its small white
blossoms in late April when it may catch the last spring snows.




                            Composite Family
           Alpine Sunflower, _Hymenoxys grandiflora_, PARKER


    [Illustration: {uncaptioned}]

Flower head is 3 to 4 inches across, the central disk, an inch in
diameter, made up of over a hundred tiny, tubular, golden florets,
surrounded by about 30 bright yellow rays which are flat and notched at
the outer end. Plant is 5 to 15 inches tall of one or several woolly
stems, with leaves divided into several narrow lobes. Grows on alpine
slopes. June-July.

This woolly-stemmed, dwarf sunflower, sometimes called
old-man-of-the-mountains, or sun-god, is a startling surprise for the
newcomer to our above-timberline tundras. One expects smaller more timid
flowers here, and so at first the big bright faces of these plants seem
out of place. Then we come to love them for their gay defiance of tough
growing conditions and think of them as the proper guardians of high
windy places. Whole colonies of them will be found with all the flower
heads faced in the same direction. This will be a direction from which
they receive strong light, and is a form of heliotropism. The stems,
however, do not twist through a full half circle each day to follow the
sun.




                            Composite Family
                 Thistle, _Circium undulatum_, SPRENG.


    [Illustration: {uncaptioned}]

Flower heads, 1½ to 2 inches broad, are solitary at the ends of stems
and branches, and made up of numerous (100 or more) rose-colored,
tubular florets fluffing out widely at their tops and grouped tightly
together at their bases into an involucre made of many little,
overlapping green bracts. Plant is about 3 feet tall with gray-green
deeply cut leaves; stem and leaf ribs armed with prickles. Grows on
plains, extending into foothills. Blooms May-September.

Thistles of some sort are found in all parts of Colorado. Above
timberline they take on grotesque shapes. In one, high-altitude thistle,
_Circium hookerianum_, the whole woolly top of the plant, formed of
compressed leaves and inconspicuous flower heads, bends over to resemble
the head and neck of some shaggy animal. In our sub-alpine hay meadows a
different species, _Circium drummondii_, may spread flat on the ground
with no main stem and keep its flower heads so low that the mowing
machine goes right over it catching only tops of a few leaves. On the
plains are other species with shaving-brush-like flower heads. In spite
of the prickles on their leaves and stems, horses nip off the flower
heads and eat them with relish. Donkeys and mules seem to like them even
better.




                        CLASSIFICATION OF PLANTS


All plants are related to each other in the sense that every one of them
is descended from a common primitive uni-cellular life form which came
into existence on this planet millions of years ago. As the remote
progeny of that ancestral cell, or group of cells, became scattered over
the earth and faced diverse conditions, which in turn changed with the
ages, these millions of related organisms exhibited profound changes
such that the differences in form, size and structure have become more
noticeable than are the badges of common inheritance. This is the
process called Evolution. Changes are established so slowly, however,
that the immediate descendants of any particular plant, or the offspring
from cross-pollination within a closely related group, will continue for
many generations to be substantially identical in structure with the
parents. As long as substantial identity in structure exists, all of
these individual plants form a single “species.” As these species are
discovered, botanists give each of them a Latin name. Within Colorado
over 2000 such separate species of flowering plants are known. Minute
variations such as color of petals or degree of hairiness of leaf or
stem are treated as “varieties” within the species.

Many thousands of these substantially identical plants may be found
scattered over parts of a state, or over several states, or even
throughout a life zone area comprising parts of several continents.
Within the life zone favorable to them, the only geographical limits
seem to be those affecting distribution of live seed.

In the search for plants, many different species are found, either in
the same or more often in different localities, in which the
resemblances are close; in fact many parts are almost identical, but
persistent differences are also present. A common ancestor several
hundred or several thousand years back may have existed, but
evolutionary changes have brought noticeable differences in the
respective descendant groups. If the changes are not too great,
especially if the mechanisms of reproduction have not been so greatly
changed as to make cross-pollination totally impossible between plants
of the several species, these related species, wherever they may have
been found, are said to comprise a “genus.” To this, also, a Latin name
is given. _Lillium_, for example, is the generic name of all true lilies
everywhere; _umbellatum_, however, is the specific name of the group to
which our Colorado mountain lily belongs; and “_Lillium umbellatum_” is
the full name of the plant shown on page 10.

Still greater differences in plant and flower structure are found,
coupled, however, with strong resemblances in significant parts of the
structure. This has led to grouping a considerable number of genera
together into a “family.” Latin names also are given to the families.
For these names there are, in most cases, well established English
equivalents which we have used here without repeating the more technical
family name. Within each family all genera and each species of every
genus will exhibit strong resemblances in the mechanism of seed
production, and the general pattern of the organs of reproduction will
be recognizably similar. For example, all species in the rose family
(with very few exceptions) have numerous stamens arranged in whorls;
they also have a calyx formed of five sepals joined together at the
base.

Other groupings, such as “Orders” comprised of several families, or
“tribes” composed of several genera within a family, are used by
botanists, but for the purposes of this booklet we have used only the
names of families, genera and species.

To the amateur one of the most interesting phases of plant
classification is the way in which, as we pass from one life zone to
another, or from one part of the state to another part within the same
life zone, we find that a plant species which we have observed at one
spot, is replaced, at another, by a different species within the same
genus. We find our white mariposa, _Calochortus gunnisonii_, on the east
side of the mountains, then, in flat clay plains in southwestern
Colorado, we find the sego lily, Calochortus nuttallii, which is a
similar, but quite distinct mariposa with cream-colored petals and a
crooked, much shorter stem. Beyond the boundaries of Colorado numerous
other species of Calochortus are found, all of them different from ours,
but all of them quite obviously mariposas.




          HOW PLANT POPULATIONS MAINTAIN THEMSELVES AND SPREAD


Infant mortality is high and life expectancy short among the flowering
plants. They not only struggle against extremes of climate, but they are
the primary food of the animal kingdom, and so pursued by creatures that
have the advantages of sight and locomotion. It is only by marvelous
fecundity and by ingenious devices for seed dispersal that plants
maintain their position on the earth.

The first objective of every plant is to produce fertile seed in as
large a quantity as the supplies of food and moisture and the length of
season will permit. Pollination, which brings about the merging of the
male and female cells, is essential to seed production. The majority of
plants combine in a single flower stamens which carry in anthers on
their tips the male element pollen and one or more pistils which hold at
their base ovaries containing the female cells. These ovaries are
reached by the pollen through the style and the stigma at its tip. The
flower may thus fertilize itself in most species, but cross-pollination
from other plants of the same species makes for more vigorous stock. The
showy petals and petal-like sepals, which draw our eyes to flowers, make
the flower conspicuous also to bees, moths, and even birds which act as
pollen bearers. Other lures to this same end are fragrances and nectar.
The detailed mechanisms by which the various plants increase the
likelihood of cross-fertilization, within the brief period that any
given set of cells is capable of fertilization, are numerous indeed and
a fascinating study.

In most plants, seed develops and becomes fully ripe in a matter of
weeks after fertilization has occurred. It is also commonplace for a
single flower to produce a seed pod or other fruit which may contain
hundreds of separate perfect seeds.

The next step is to scatter this seed over an area wide enough to reduce
the risk of all of them perishing at once, and also wide enough to keep
the survivors from competing too closely with each other for soil,
moisture and sunlight. Here again fascinating devices come into play.
Building each seed with a plume or bit of fluff at its tip so that it
can be carried far by wind, is one of the commonest tricks. Other seeds
float easily on water and so reach new sites. Other seeds invite being
eaten by birds or beasts, and depend upon a fraction of them either
being carelessly dropped before being swallowed, or having tough enough
shells to resist digestion. Quite a number of plants produce seed pods
which, when they become thoroughly dry split open with a jerk flipping
seeds over distances of several feet. Finally there are the various burs
and barbed seeds that are carried for miles by animals and by man.

Seeds thus become scattered over the earth, and so numerous and
efficient are the devices of dispersion that in the course of years the
seeds from a single plant colony, and from the successive new outlying
colonies it founds, may become spread over miles of distance. Only a few
barriers completely stop such spreading. Oceans, high mountains and
broad deserts are the most effective barriers, but even they do not
always stop every seed of every plant.

This spread of seeds pays little attention to life zone limits, or to
such interference as rivers, hills or local barren areas may present.
Over and past all of such minor obstacles the flow of seed rolls.

The final problem for the seed is how to germinate and become
established in the place it lands. If that place is totally unsuitable
for the particular species, the answer there is failure. Many seeds may
invade a locality too dry for their development. In such a case, even if
germination occurs, all such seedlings will die before a single plant
matures. Heavy frost may act as a like absolute veto to other seedlings
that venture too high in altitude or too far north in latitude for their
own limitations. By forces such as these, each species of plant stays
contained within limits beyond which it cannot become established, even
though individual seeds may in great numbers invade impossible
localities.

Mature plants may tolerate conditions which wipe out all tender
seedlings of the same species. This leads to interesting patterns of
plant distribution in semi-desert areas, such as occur in parts of
Colorado. Once or twice in a century a series of two, three, or even
five successive years may occur when the soil is moist and
extraordinarily favorable to plant growth throughout weeks or months of
the spring and summer. In these special times seeds that have invaded a
usually hostile area may, if they have retained fertility, germinate,
push their roots deep, and become so vigorous that when normal dry years
follow these particular plants live on and thrive for the remainder of
their lives, even though their own seeds fall on barren ground and the
species maintains only a precarious or temporary foothold in the area.

Governed by forces such as these, and limited by competition with each
other, plant species have for ages taken their places in the global
economy and carried out their part of the commandment to be fruitful and
multiply. Otherwise we and the animals we prey upon could not exist.




                              FLOWER FORMS


The four flowers sketched below with supplementary drawings of their
separate parts, give only a small sample of the infinite structural
variety found among flowering plants.

    [Illustration: A Yucca, illustrating features which are found in
    several other lilies.]

  perianth segment
  stigma
  anther
  style
  ovary
  pedical
  stem
  Detail of stamen
    pollen
    anther
    filament

    [Illustration: A Buttercup. This particular one has showy sepals but
    no petals.]

  group of styles
  sepal
  group of
  stamens
  ovary
  pedical
  single sepal
  Detail of stamen

    [Illustration: A Penstemon. Here a calyx is present formed of 5
    sepals united at their base, the petal parts are fully united into a
    tubular corolla terminating at its throat in 5 unequal lobes.]

  lobe of corolla
  sterile stamen
  anther
  stigma
  style
  sepal
  ovary
  calyx
  pedicel
  Details
    beard
    filament
    anther
    filament

    [Illustration: A Composite flower head, made up of numerous complete
    and separate flowers, enclosed at their bases in an involucre made
    up of many overlapping bracts.]

  (right half cut away and all other florets removed)
    bracts of involucre
    tubular floret
    receptacle
    ray floret
  stigma
  style
  stamen
  corolla tube
  ovary
  receptacle




                              PLANT PARTS


    [Illustration: This sort of inflorescence is known as a raceme.
    Larkspurs and many other plants arrange their flowers in this way.]

  pedicel
  stem

    [Illustration: When the flowers are clustered at ends of radiating
    pedicels as shown here the inflorescence is an umbel. All the
    parsleys follow this general pattern.]

  pedicel
  bract
  scape

    [Illustration: Onions and some other lilies grow in this pattern.]

  stem
  bulb

    [Illustration: Many plants, including penstemons, grow this way.]

  stem
  root crown or caudex

    [Illustration: Prickly Poppy has this sort of root and stem system.]

  main stem
  tap root
  root

    [Illustration: Shooting Star grows this way.]

  scape




                               LEAF FORMS


    [Illustration: Simple]

  linear
  lanceolate
  ovate
  cordate

    [Illustration: Compound]

  pinnate
  pinnately
  cleft
  bipinnate
  palmate

    [Illustration: Leaf Arrangements]

  opposite
  alternate
  whorls

    [Illustration: Attachment Parts]

  stem
  petiole
  stipule




                BOOKS DEALING WITH COLORADO WILDFLOWERS


  Field Book of Western Wild Flowers—Margaret Armstrong
      C. P. Putnam’s Sons, N. Y., 1915

  Plants of Rocky Mountain National Park—Ruth E. Ashton
      Government Printing Office, 1933
      Revised edition under same title—Ruth Ashton Nelson in press, 1953

  Colorado Cacti—Chas. H. Boissevain and Carol Davidson
      Abbey Garden Press, San Marino, 1940

  Rocky Mountain Flowers—Frederic E. and Edith S. Clements
      H. W. Wilson Co., N. Y., 1920

  New Manual of Botany of the Central Rocky Mountains—John
      Coulter and Aven Nelson
      American Book Co., Chicago, 1909

  Manual of the Plants of Colorado—H. D. Harrington
      Sage Press, Ft. Collins, Colorado—in press, 1953

  American Wild Flowers—Harold N. Moldenke
      D. Van Nostrand Company, Inc., N. Y., 1949

  Meet the Natives—M. Walter Pesman
      Denver, Colorado, 1943

  Flora of Colorado—P. A. Rydberg
      Ft. Collins, Colorado, 1906

  Flora of Rocky Mountains and Adjacent Plains—P. A. Rydberg
      New York, 1917

  The Flora of Boulder County, Colorado—William A. Weber
      University of Colorado Museum




                        OTHER MUSEUM PICTORIALS


1. Nature Photography with Miniature Cameras—Alfred M. Bailey

2. The Story of Pueblo Pottery—H. M. Wormington and Arminta Neal

3. Stepping Stones Across the Pacific—Alfred M. Bailey and Robert J.
      Niedrach

4. Fossil Mammals—Harvey C. Markman

5. Nature Photography with High-Speed Flash—Walker Van Riper, Robert J.
      Niedrach and Alfred M. Bailey

6. Laysan and Black-footed Albatrosses—Alfred M. Bailey

7. The Hawaiian Monk Seal—Alfred M. Bailey




                                 INDEX


                                   A
                                                                  _Page_
  _Abronia fragrans_                                                  14
  Alpine forget-me-not                                                46
  Alpine sunflower                                                    55
  _Anemone globosa_                                                   20
  _Aquilegia coerulea_                                                24
  _Argemone intermedia_                                               25
  _Asclepias speciosa_                                                43


                                   B
  Bird-bill                                                           41
  Brook primrose                                                      40
  Bush cinquefoil                                                     29
  Bush morning-glory                                                  44


                                   C
  Cactus                                                           35-36
  _Calochortus gunnisonii_                                            11
  _Castilleja integra_                                                49
  Cattail                                                     Back Cover
  _Chimaphila umbellata_                                              39
  _Chrysothamnus nauseosus_                                           52
  _Cirsium undulatum_                                                 56
  _Claytonia lanceolata_                                              17
  Columbine                                                           24
  _Cypripedium calceolus_                                             13


                                   D
  Deer clover                                                         31
  _Delphinium nelsonii_                                               21
  _Dodecatheon radicatum_                                             41


                                   E
  Easter daisy                                                        53
  _Echinocereus triglochidiatus_                                      35
  _Epilobium angustifolium_                                           38
  _Erigeron speciosus_                                                54
  _Eriogonum umbellatum_                                              15
  _Eritrichium elongatum_                                             46
  _Erysimum asperum_                                                  26
  _Erythronium grandiflorum_                                          12
  Evening primrose                                                    37


                                   F
  Fireweed                                                            38
  Fleabane                                                            54
  Fringed gentian                                                     42


                                   G
  _Gaillardia aristata_                                               51
  _Gentiana elegans_                                                  42
  _Gilia aggregata_                                                   48
  Glacier lily                                                        12
  Globe anemone                                                       20
  Globe flower                                                        23
  Golden banner                                                       33


                                   H
  _Hymenoxys grandiflora_                                             55


                                   I
  Indian paintbrush                                                   49
  _Ipomoea leptophylla_                                               44


                                   L
  Lady’s slipper                                                      13
  Lambert’s loco                                                      32
  Larkspur                                                            21
  _Lathyrus stipulaceus_                                              30
  _Leucocrinum montanum_                                               9
  _Lilium umbellatum_                                                 10
  Loco                                                                32


                                   M
  Mariposa                                                            11
  _Mentzelia nuda_                                                    34
  Milkweed                                                            43
  Moss campion                                                        18


                                   N
  Nelson’s larkspur                                                   21


                                   O
  _Oenothera brachycarpa_                                             37
  _Opuntia trichophora_                                               36
  _Oxytropis lambertii_                                               32


                                   P
  Paintbrush                                                          49
  Pasque flower                                                       19
  _Penstemon unilateralis_                                            50
  _Phacelia sericea_                                                  45
  Pipsissewa                                                          39
  _Polemonium viscosum_                                               47
  _Potentilla fruticosa_                                              29
  Prairie pea                                                         30
  Prairie snowball                                                    14
  Prickly pear                                                        36
  Prickly poppy                                                       25
  _Primula parryi_                                                    40
  _Pulsatilla ludoviciana_                                            19
  Purple fringe                                                       45


                                   Q
  Queen’s crown                                                       28


                                   R
  Rabbit brush                                                        52
  _Ranunculus adoneus_                                                22
  _Rumex venosus_                                                     16


                                   S
  Sand begonia                                                        16
  Sand lily                                                            9
  _Saxifraga rhomboidea_                                              27
  Scarlet gilia                                                       48
  _Sedum rhodanthum_                                                  28
  Shooting star                                                       41
  _Showy fleabane_                                                    54
  _Silene acaulis_                                                    18
  Sky pilot                                                           47
  _Snowball saxifrage_                                                27
  Snow buttercup                                                      22
  Spanish bayonet                                            front cover
  Spring beauty                                                       17
  Stickweed                                                           34
  Strawberry cactus                                                   35
  Sulphur flower                                                      15


                                   T
  _Thermopsis divaricarpa_                                            33
  Thistle                                                             56
  _Townsendia sericea_                                                53
  _Trifolium nanum_                                                   31
  _Trollius laxus_                                                    23
  _Typha latifolia_                                           Back Cover


                                   W
  Wallflower                                                          26
  Wood lily                                                           10


                                   Y
  Yellow evening primrose                                             37
  Yellow lady’s slipper                                               13
  _Yucca glauca_                                             front cover




                             Cattail Family
                     Cattail, _Typha latifolia_, L.


                                                             BACK COVER⇒

The flower spike forms the top 6 to 10 inches of a stiff rush-like stem
which rises from a sheath of long, narrow, flat leaves to a total height
of about 4 feet, the leaves rising slightly higher than the stem. The
top 3 or 4 inches of the flower spike is composed of numerous male
flowers producing only pollen and early dropping off to leave a bare,
rather sharp, stem tip; the lower 4 or 5 inches of the flower spike is
composed of thousands of female flowers packed so tightly together as to
give the appearance of a smooth, rich-brown cylinder, more than an inch
in diameter, which finally breaks up into fluffy seeds. Forms solid
colonies in marshy places in plains, foothills and lower montane zones.
Blooms first appear about July, and become mature in September-October.

    [Illustration: The Museum]

    [Illustration: {uncaptioned}]




                          Transcriber’s Notes


—Silently corrected a few typos.

—Retained publication information from the printed edition: this eBook
  is public-domain in the country of publication.

—In the text versions only, text in italics is delimited by
  _underscores_.