Chapter I: Foreword (1)

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

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

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

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

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

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

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.

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

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.

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

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.

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.

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.

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!

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

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.

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

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.

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

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

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.

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

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

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.

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

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

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.

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.

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.

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

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.

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.

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.

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

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

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.

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.