OK N4J. ±902 mi^B LIBRARY AT CORNELL UNIVER*^' !S8 924 05 III 783 789 The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924051783789 TWENTIETH CENTURY TEXT-BOOKS EDITED BY A. F. NIGHTINGALE, Ph.D., LL. D. SUPERINTENDENT OF SCHOOLS, COOK COUNTY, ILLINOIS TWENTIETH CENTURY TEXT-BOOKS AN ANALYTICAL KEY TO SOME OF THE COMMON FLOWERING PLANTS OF THE ROCKY MOUNTAIN REGION BY AVEN NELSON, A. M. PROFESSOR OF BOTANY IN THE UNIVERSITY OF WYOMING NEW YORK D. APPLETON AND COMPANY 1908 Copyright, 1902 By D. APPLETON AND COMPANY Puhlished June, 1902 PREFACE There are approximately 3,000 species of indigenous flower- ing plants in that portion of the United States known as the Rocky Mountain region. Many of these by reason of their abundance, attractiveness, and conspicuous characters afford material both suitable and available for use in the introduc- tory courses in botany in high schools and colleges. In spite of the fact that botany to-day must take cognizance of several new phases of the subject, it must still be admitted that a certain amount of work in systematic botany offers a point of contact with Nature that is of inestimable value. But justice to the co-ordinate and equally important divisions of the subject requires that systematic botany should take no more than a co-ordinate place. For various reasons it has been found inexpedient in many instances to attempt the use of the standard manuals. It is hoped that this brief synoptical Key may meet the needs of such courses, and that the beginner, discovering for himself the names of a few of the common plants of his neighborhood, may develop an interest in his flora that will later make him, in some cases, a critical student of it. This booklet is not offered as- a substitute for a manual of the region, but rather, as an introduction, which will prepare the student for the better use of a manual. It seems best, there- fore, to include only the commoner species, and especially those that blossom during the spring and early summer. To select a VI KEY TO THE SPECIES few hundred that should give a considerable range of choice to the many schools of this vast intermountain country has been no easy matter. If it has been successfully done, much of the credit is due to the following persons, who have kindly sup- plied lists of plants that it seemed to them well to include : Mr. George E. Osterhout, New Windsor, Col. ; Prof. Eugene Beardsley, Colorado State Normal School ; Prof. Francis Rama- ley, University of Colorado ; Prof. Ellsworth Bethel, Denver High School ; Mr. H. L. Shantz, Colorado College ; to each of whom the author's thanks are due. By this co-operation it is thought that a list has been secured that will prove useful from Montana to New Mexico, and with a somewhat variable east- ward and westward extension. In spite of the care that has been exercised, some species that would be particularly availa- ble in some localities have no doubt been omitted. It will be greatly appreciated if teachers will report such species so that they may be included in subsequent editions. To secure the best results from the use of this Key in the classroom, the teacher must keep in mind the following things : (1) That the number of species included is limited. Therefore it would be very unwise to permit students to attempt to name a miscellaneous collection of plants by means of it — a practice that would surely result in confusion and discouragement. Much better lay before the class material of such species only as are known to be included. These will furnish the discipline sought, with the added enthusiasm that comes from something actually accomplished. (2) That the descriptions are brief, no attempt having been made to distinguish a given species froin all other species in that genus, but only from the other species in this Key. To do even this it will sometimes be necessary to keep in mind that the analytical keys are an essential part of the description, since the statements in the keys are not usually repeated. (3) That while the aim has been to avoid as far as possible strictly technical terms, yet conciseness has necessi- KEY TO THE SPECIES VU tated the use of many ; therefore, one or more dictionaries, or manuals containing glossaries, ought to be always at hand. (4) That it is always well to have one or more copies of the standard manuals at hand for reference (Coulter's is the only one out at present devoted to this region in particular, though many of our species will be found in Gray's and in Britton's). Lastly, I wish to atsknowledge my indebtedness to the first in this series of Keys, viz., that prepared by Dr. Coulter for the Eastern United States. In so far as the species used are the same for the two regions, I have taken the liberty of adopting not only the same mode of treatment, but in many instances the descriptions in their entirety. I am further deeply in- debted in many ways to Dr. Britton's recent Manual and to Dr. Coulter's Manual of the Rocky Mountains. AvEN Nelson. Univeksitt of Wyoming, Laramie, March, 190S. KEY TO THE FAMILIES Class I. GYMNOSPERMS Ovules naked upon a scale or bract (not inclosed in an ovary). Besinous trees or shrubs with evergreen leaves .... Plnacese B Class II. ANGIOSPERMS Ovules inclosed in an ovary. Sub-class (I) MONOCOTYLEDONS Parts of the flower usually in threes (never in fives) ; leaves mostly parallel- veined ; ours all herbs. 1. Flowers usually with neither calyx nor corolla and massed upon a more or less fleshy axis (spadix) Marsh or aquatic plants, with linear leaves. Flowers in a dense cylindrical terminal spike .... Typhacese 7 Flowers in globular heads . Sparganlacese 7 3. Flowers ivith calyx and corolla alike (perianth) or different, not collected upon a spadix a. Ovary superior (appearing within the flower) Pistils numerous AlismacesB 7 Pistil one. Perianth of similar divisions or lobes. Styles 3 ; fruit a capsule . Melanthacese 8 Style 1 ; fruit a capsule I,iliaceae 9 Style 1 ; fruit a berry .... . Convallariaceae 11 Perianth of 3 green sepals and 3 colored petals . . Commelinaceae 8 b. Ovary inferior (appearing below the flower) Stamens 3 ... . . Iridaceae 12 Stamens 1 or 2 and massed with the style ; flowers irregular Orchldaceae 12 Sub-class (II) DICOTYLEDONS Parts of the flower usually in fives or fours ; leaves mostly net-veined. 1 2 KEY TO THE SPECIES A. ARCHICHLAMYDEiE Corolla either wanting (apetalous) or of separate petals (polypetalous). 1. Corolla wanting, and sometimes the calyx also (naked) a. Flowers in aments (dense scaly spikes) ; frees, shrubs or vines Calyx wanting. A single flower in the axil of each bract ; fruit a pod with numerous downy-tufted seeds Salicacese 14 Pistillate flowers 3 or 3 in the axil of each bract ; fruit a winged or wingless nut Betulacese 15 Calyx present. Fruit a nut inclosed by a cup or involucre Fagacese 16 Fruit an achene ; twining vines . . Moraceae 17 b. Flowers not in amenta * Shrubs or trees Leaves opposite, palmately lobed ; fruit in pairs and winged . Aceraceae 47 Leaves alternate, simple. Fruit winged all around .... . . TJlmaceae 17 Fruit berry-like . . ... . lElea.gna.cesei 52 * * Herbs ; sepals sometimes petal-like Pistils more than one, separate or nearly so . . . Banunculaceae 23 Pistil one ; ovary superior. Ovary 5-celled and 5-beaked Crassulacese 33 Ovary 3-celled, becoming a 3-lobed capsule . . . Euphorbiaceae 4Q Ovary 2-celled, becoming an emarginate capsule , Scrophulariacese 73 Ovary 1-celled, becoming an achene Polygonaceae 18 Pistil one ; ovary inferior. Leaves alternate ; fruit dry, nut-like .... Santalacese 17 Leaves opposite ; fruit inclosed by the calyx . . , Nyctaginaceie 20 2. Calyx and corolla both present^ the latter of separate petals (polypetalous) it. Stamens more than 10 Trees, shrubs, or woody vines ; leaves alternate. Pistils numerous, leaves with stipules Bosaceee 35 Pistil one ; fruit fleshy. Ovary l-celled ; fruit a drupe (stone fruit) .... Drupaceae 40 ■ Ovary 5-celled ; fruit a pome (calyx fleshy) .... Pomaceee 39 Herbs. Pistils several. Stamens on receptacle Banunculacese 23 Stamens on the calyx Rosaceae 35 Pistil one. Stamens separate. Sepals 2 . Papaveraceae 27 Sepals 4 Capparidaceae 31 Sepals numerous Cactaceae 51 Calyx 5-Iobed . . . . ... lioasacese 50 Stamens united into a column . . ... Malvaceae 48 KEY TO THE SPECIES b. Stamens not more than 10 Trees, shrubs, or woody vines ; fruit fleshy. Fruit a drupe (stone fruit) Coruacese 57 Fruit a berry. Stamens alternate with petals . . Grossulariaceae 34 Stamen3 opposite petals. Stamens 4 or 5 ; climbing by tendrils . . . Vitaceee 48 Stamens 6 ; not climbing Berberidacese 37 Herbs. Pistils more than one Crassulaceae 32 Pistil one. Ovary 1-celled. Corolla regular or nearly so. Sepals 4 ; leaves compound .... Capparidacese 31 Sepals 4 or 5 ; leaves simple . . Caryopliyllacese 31 Sepals 3 ; leaves fleshy .... Fortulacaceie 20 Corolla irregular. Stamens 6, In 2 sets . . . . Papaveraceae 27 Stamens 5 ; one petal spurred . . Violaceae 49 Stamens 5 or 10 ; petals not spurred . . Papilionaceae 40 Ovary 2- or 5-celled. Ovary superior (appearing within the flower). Ovary 2-celled. Stamens tetradynamous, petals 4 . . Cmciferoe 28 Stamens 10. petals 5 . . . Saxifragaceae 32 Ovary 5-celled. Leaves simple, flowers regular. Anthers opening by holes at the apex Pyrolacese 57 Anthers opening lengthwise. Leaves broad, lobed or toothed Geraniaceae 46 Leaves narrow, entire . . Xjinacese 46 Leaves trifoliolate Oxalidaceae 47 Ovary inferior (appearing below the flower). Fruit a 4-celIed pod Onagracese 52 Fruit splitting into 1-seeded halves . . TTmbelU ferae 55 B. SYMPETALiE Corolla with petals united (sympetalous), at least at base, or rarely wanting. 1. Stamens more numerous than the lobes of the corolla Ovary 1-celled. Sepals Papilionaceae 40 Sepals 3 . . . . • Papaveraceae 27 Ovary 3 to many-celled. Stamens separate, style 1 ; fruit a berry. Ovary superior Ericaceae 58 Ovary inferior Vacciniaceae 58 Stamens united into a column Malvaceae 48 KEY TO THE SPECIES 2. Stamens as many as the lobes of the corolla or fewer Stamens opposite the corolla-lobes Priniulacew 59 Stamens alternate with the corolla-lobes, or fewer. ii. Ovary superior (appearing within the flower) Corolla regular or nearly so. Stamens as many as the corolla-lobes. Ovaries 2, becoming a pair of follicles. Pollen powdery .... Apocynaceae 61 Pollen in 2 solid waxy masses . . . Asclepiadaceae 62 Ovary 1. Ovary deeply 4-lobed around the style. Leaves alternate . . . Boraginacege 66 Leaves opposite .... . . Labiatui 69 Ovary not lobed, 1-celled, Corolla scarious and veinless ; leaves entire Flantaginacese 78 Corolla not scarious ; leaves not entire , Hydrophyllacese 65 Ovary 2- to lO-eelled ; stamens on the corolla-tube. Stamens 4. Pod opening by a lid . . . . PlantaginacesB 78 Pod not opening by a lid . . . . Verbenaceae 68 Stamens 5. Fruit of 2 or 4 seed-like nutlets . BoraginacefB 66 Fruit a many-seeded berry . . . . Solaiiaceae 71 Fruit a many-seeded capsule. Style short or none ; stigma of two lamellae Gentiana 60 Style slender ; stigma entire Scrophulariaceae 73 Fruit a few-seeded capsule. Style 1, 3-cleft . . . Polemoniaoese 63 Styles 1 or 2, entire or 2-cleft . Convolvulaccie 62 Stamens fewer than the corolla-lobes. Stamens 4 Terbenaceae 68 Stamens 2. Stems naked PlantaginaccEe 78 Stems leafy .... . Scrophulariaceae 73 Corolla irregular, or rarely wanting. Ovules and seeds solitary in the cells. Ovary 4-lobed Labiatse 69 Ovary not lobed . . Verbenacepe 68 Ovules and seeds 2 or more in each cell . . . Scrophalariacese 73 b. Ovary inferior (appearing below the flower) Flowers not in an involucrate head. Leaves alternate Campanulacese 81 Leaves opposite. Stamens 4 or 5 ; fruit berry-like .... Caprifoliaceae 78 Stamens 3 ; fruit dry, 1-seeded . . . Valerianaceai 80 Flowers in an involucrate head. All the flowers with strap-shaped corollas . . . Ciclioriaceae 81 All but the ray flowers with tubular corollas . , Compositae 83 KEY TO THE SPECIES I. PINACEiE (Pine Family) Trees or sometimes shrubs, evergreen, more or less resinous ; leaves needle-shaped or scale-like ; staminate and pistillate flowers on the same individual (except in Juniperus) ; the male clusters of an indefinite number of stamens only ; the female of few to many scales which become in fruit a dry cone, with 2 or more ovules at or on the base of each scale. In Juniperus the fruit is small, semi-fleshy, and berry-like. (See Plant Structures, Conifers, p. 191.) » Fruits becoming dry cones. 1. Pinus. Leaves in bundles of 2-5. 3. Flcea. Leaves single, sharp-pointed. 3. Pseudotsuga. Leaves single, blunt-pointed. * * Fruits semi-fleshy, berry-like. 4. Juniperus. Leaves scale-like or awl-shaped. , 1. PINUS (Pine) Trees ; leaves of two kinds, the primary ones early deciduous, the secondary (ordinary foliage) slender, needle-shaped, in bundles of 2-!>, united at the base by a sheath formed from the bud-scales ; cones large, the scales becoming thick and woody and bearing 2 seeds on the base of each scale, not maturing till the second year. * Leaves 2 in each bundle. ■*- Scales tipped with delicate recurved prickle ; seeds winged. 1. Pinus Murrayana " Oreg. Com." (Lodgepole Pine). Usually growing in dense groves or forests and then tall (15-30 m.) and very slender, nearly devoid of branches except at the summit ; if growing in more open ground, more freely branched and stockier ; leaves semi-terete, rather rigid, about 5 cm. long ; cones small, adhering tenaciously to the branches, which are often marked by the dead, persistent cones of the previous years ; scales closely compacted, with quadrangur lar ends. Common ; preferring moist ground. -*- Scales without prickles ; seeds wingless. 2. Pinus edulis Eagelm. (Pinon or NnT Pine). A low round-topped tree, freely branched, often from the base ; leaves paired (rarely in threes), 3-4 cm. long, rigid ; cones of few scales, sub-spherical ; scale with thickened pyramidal tips ; seeds edible. * ♦ Leaves 3 in each bundle. 5 6 KEY TO THE SPECIES 3. Pinus scopulOTum (Engelm.) Lemmon (Rock Pine). A large tree, 25-40 m. high, 1-2 m. in diameter ; leaves 12-16 cm. long, mostly 3 in each bundle (rarely- only 2), in dense brush-like bunches at the ends of the branches ; cone 7-10 cm. long ; scales thickened at the tip, which bears a sharp, recurved prickle. • ♦ ♦ Leaves 5 in each bundle. 4. Pinus flexilis James (Limber Pine). A tree of wind-swept hills and sum- mits, scattering, often much distorted ; branches very flexible ; leaves 4-7 cm. long ; cones light colored, 8-10 em. long, egg-shaped ; scales with broad, slightly thickened tips, widely spreading when mature. 3. PICEA (Spruce) Spire-shaped trees, often tall and slender ; leaves spirally arranged, jointed near the base, falling when dry and leaving the branchlets rough with the project- ing bases ; cones pendulous, oblong, of numerous scales bearing two ovules. * Branchlets pubescent ; leaves abruptly sharp-pointed. 1. Picea iEngelmanni Engelm. (Engelmann Spruce). A large tree of the higher mountains, forming dense forests ; on alpine summits depressed and matted ; leaves keeled, 2-3 cm. long ; cones solitary, oblong, about B cm. long. * Branchlets smooth and shining ; leaves needle-pointed. 2. Picea Parryana (Andre.) Parry (Blue Spruce). A small, conical tree with soft wood, and smooth bark when young ; leaves slender, sharply 4-angled, usually bluish green ; cones narrowly oblong, 5-10 cm. long, drooping, generally in clusters, and numerously crowded at the summit of the tree. This tree prefers moist situations. It is extensively used for ornamental planting, tor which its beautiful color and handsome outline admirably flt it. As the chosen '* State Tree " of Colorado it is of interest. 3. PSEUDOTSUGA (False Hemlock-spruce) A large, stately tree, occurring in the mountains at middle elevations, on moist slopes and plateaus ; leaves with a short petiole, twisting on the base so as, to appear comb-like on the branches, which are smooth when the leaves have fallen and marked only by oval scars. 1. Pseudotsnga taxifolia (Lam.) Britt, (Douglas Spruce). Often 35-50 m. high ; bark thick and fnrrowed ; leaves flattened, blunt pointed, whitish below, 2 cm. or more in length ; cones oval, 7-9 cm. long, perfectly characterized by the fringe-like, somewhat reflexed, 3-pointed bracts which project from among the scales of the cone. 4. JUNIPERUS (Juniper) • Leaves short, blunt and scale-like (except in seedlings). 1. Juniperus scopulorum Sargent (KocKV Mountain Juniper). Becoming a low, round-topped tree with thick trunk, or sometimes freely branched from the base (rarely; Jn very exposed situations, a mere shrub); leaves in pairs, very short, nearly clothing the branchlets ; berries very numerous, not maturing till the second season, light green when young, when mature blue with whitish bloom. « « Leaves awl-shaped, prickly-pointed, 10-15 mm. long. KEY TO THE SPECIES 7 2. Junlperus Siblrica Burgsd. (Dwarf Juniper). A low-spreading shrub, rarely 1 ra. high, forming dense, usually circular patches ; leaves in 3s, crowded, rigid, channeled, and often whitish above ; berries small, fleshy^ bluish, 1-3-seeded. Rocky hillsides. II. TYPHACEiE (Cat-tail Family) Plants of marshes and shallow ponds, with stout rootstocks and fibrous roots ; stems round and stout, with flat, striate, lin- ear leaves ; staminate and pistillate flowers on same plant in a dense terminal spike ; ovary 1-celled, becoming a 1-seeded nut- like fruit. 1. TYPHA (Cat-tail) Tall herbs with large grass-like leaves sheathing the base of the simple stem, which is terminated by a long and very dense cylindrical spike of flowers, the upper part staminate and wilting, the lower part pistillate, more compact and per- sistent. 1. Typha latifolia Linn. (Broad-leaved Cat- tail). Stem 1-2 m. high, sur- passed by the broad (16-30 mm.) leaves ; staminate and pistillate parts of the spike contiguous. (See Plant Structures, p. 239, Fig. 221.) Very abundant in ponds and on the marshy banks of streams. III. SPARGANIACEiE (Bue-keed Family) The characters of the family are nearly those of TyphacecB, except that the flowers and fruits are in dense globular heads which are subtended by leaf -like spathes. 1. SPARGANIUM Leaves broadly linear, flat, sheathing the stems at the base ; the upper heads small, of stamens only ; the lower large, of numerous pistils. 1. Sparganittm eurycarpum Engelm. (Bdr-rebd). Stems branched above, 8-15 dm. high ; fertile heads 8 cm. or more in diameter ; fruits sessile, angled, with flattened or depressed summit ; scales several from the base of each nutlet. Borders of ponds and sluggish streams. IV. ALISMACEiE ("Water-plantain Family) Marsh plants with naked stems, sheathed at the base by the petioles of the broad leaves ; sepals and petals each 3 ; stamens 6 or more ; pistils many. 1. Alisma. Stamens 6 ; carpels in a single ring on a flat receptacle. 2. Saglttaria. Stamens many ; carpels in a dense head. KEY TO THE SPECIES 1. ALISMA (Water Plantain) Marsh herbs, the naked stems freely branched above ; leaves long-petioled, nerved, ovate or oblong, with rounded base ; the small flowers in loose clusters. 1. Allsma Flantago-aquatica L. (Water Plantain). Stem 3-7 dm. high, branching above to form the long, open panicle of flowers ; leaves 5-9-nerved, with flue cross-veins ; flowers perfect ; fruit obliquely obovate, keeled on the back. Spring bogs, etc. 3. SAGITTARIA (Arrow-head) Flowers monoecious, borne in whorls of 3s, the staminate uppermost, the pis- tillate numerous. 1. Saglttaria arifolla Nutt. (Arkow-head). Growing in shallow ponds or in stream margins ; leaves sagittate, with broad blade, the apex acute, the basal lobes lanceolate, becoming acuminate; petioles and scape weak; bracts as long as the pedicels ; petals white, conspicuous ; akene obovate, winged, the very short beak erect. V. COMMELINACEiE (Spiderwokt Family) Perennial herbs, with jointed, leafy steins ; leaves linear, channeled and sheathing at base ; perianth free, of 3 green sepals and 3 blue ephemeral petals ; stamens 6 ; a single style ; and a 2- or 3-celled ovary becoming a pod. 1. TRADESCANTIA (Spiderwort) Low herbs, with nearly simple stems ; leaves narrow ; flowers in terminal umbels ; stamens densely blue-bearded. 1. Tradescantia scopulorum Rose (CLtIFP Spiderwort). Stems slender, 2-3 dm. high, sparingly branched, light green -and nearly smooth ; leaves numer- ous,, linear, mostly radical, the iavolucral ones short, unequal, and filiform ; umbels several ; flowers pale blue. VI. MELANTHACEiE (Bunch-elowee Family) Leafy-stemmed herbs with bulbs (in ours) ; leaves broadly linear, alternate ; perianth as in the Liliacece ; stamens 6, free ; fruit a 8-celled capsule. 1. ZYGADENUS (Camass) Erect perennials from onion-like bulbs; flowers in racemes, the greenish -white or yellowish segments with a gland near the basis ; capsule 3-lobed, splitting to the base at maturity. KEY TO THE SPECIES 9 1. Zyg:adenus elegans Pursh {Larob-flowered Camass). Stem i-8 dm. high; leaves glaucous, keeled, 1-2 cm. broad; flowers greenish- white, the segments obovate, 7-10 mm. long, with an obcordate glaud near the base ; capsule oblong, longer than the flower segments. In wet valleys. 2. Zygadenus falcatus Eydb. Stem stoutish, 3-4 dm. high ; leaves some- what scabrous, shorter than tfie stem, usually conduplicate and falcate ; flowers yellowish-white, the segments 5 mm. long, ovate, short-clawed ; gland semi- orbicular ; capsule ovoid-cylindrical. VII. LILIACEiE (Lilt Family) Herbs ; stems scapose or leafy, from bulbs or fleshy roots (a ■ woody caudex in Yucca) ; leaves mostly linear ; flowers per- fect ; perianth of 6 distinct segments ; stamens 6, on the recep- tacle or the tube of the perianth ; styles united ; stigma 3-lobed or entire ; ovary 3-celled, becoming a capsule. (See Plant Structures, p. 245.) * With fleshy roots from a short rootstock. 1. Lieucocrinuiu, Perianth white, with long narrow tube. * * Bulbous plants. -t- Flowers in umbels. • 2. Allium. Umbel of flowers from a, 1- or 2-leaved scarious sheath ; onion scented. -(- -*- Flowers solitary, racemed or sub-umbellate. ** Perianth segments all alike. 3. Iiilinm. Perianth large, erect, funnel-form, orange-red. 4. Fritillaria^ Perianth nodding, small, reddish-brown, segments not reflexed. 5. Erythronium. Perianth nodding, yellow, segments reflexed. ++ ++ Outer perianth segments narrower than the inner. 6. Calocliortus. Flowers erect, outer segments small, the inner with a hairy gland at base. * * * With large woody caudex. 7. Yucca. Leaves rigid, sharp-pointed, numerous. 1. LEUCOCRINUM Stemless, the numerous fleshy roots from a short rootstock which bears the several linear leaves ; flowers few to many from the crown of the rootstock. 1. Leucocrlnum montanum Nutt. (White Mountain Lily). Leaves thick, surrounded at base by scarious bracts ; flowers white, the tube slender, 3-5 cm. long, the segments spreading ; stamens on the tube ; style long, with dilated stigma. The fragrant blossoms appear just above the ground in early spring. 3 10 KEY TO THE SPECIES 2. ALLIUM (Onion) Strong-scented herbs, with coated bulb and a basal cluster of leaves ; stem naked, bearing a terminal umbel of small flowers ; perianth of distinct (or nearly SO) divisions and a 3-lobed pod. 1. Allium cernuuiu Roth. (Nodding Wild Onion). Stems slender, from deep-seated, clustered bulbs with long necks, S-4 dm. high ; leaves flat, 2-4 mm. wide; umbel nodding; pedicels slender, long; flowers rose-tinted. Occasional; in the valleys among- the foothills. 2. Allium reticulatum Don. (Wild Onion). Bulb rather large, the coats strikingly fibrous-reticulate ; stem 1-2 dm. high ; leaves narrow, channeled ; the flowers white or pinkish, on short pedicels, each bearing two crests. In sandy soil of plains and valleys. 3. LILIUM (Lily) Bulbs of thick scales ; Rtems simple, with scattered or whorled leaves, flowers 1-several, large, showy, erect or drooping, funnel-form or bell-shaped ; stamens and style long ; anthers versatile. > 1. Liilium uiontanum Aven Nelson (Mountain Lily. "Tiger Lily''''). Bulb depressed-globose, of thick fleshy scales ; stem 3-4 dm. high ; leaves smooth, dark green, alternate except the uppermost whorl of 5-7, lanceolate, sessile ; the segments of the single erect flower elliptic-oblong, tapering to both ends, brownish- red to orange-red, the base of the inner face dotted with purplish-black spots ; stamens and stigma purplish ; capsule oblong-cylindric. In moist thickets near mountain streams. 4. FRITILLARIA Much like Lilium ; flowers small, bell-shaped, nodding, leafy-bra'cted ; anthers not versatile. 1. Fritillaria atropurpurea Nutt. (Purple Fritillaria). Bulbs from thick, nearly rice-shaped scales ; stems 1-2 dm. high ; leaves scattered or whorled ; flowers 1^, dull-purple and mottled; stamens shorter than the narrowly oblong perianth segments ; capsule erect, obovate, acutely angled. 5. ERYTHRONIUM (Dog-tooth Violet) Herbs from deep-set bulbs; leaves only 2, smooth, flat, shining, sheathing the base of the naked stem ; flowers 1 or more, nodding ; perianth of six separate and recurved segments. 1. Erythronium parviflorum (Wats.) L. N. Goodding (Colorado Dog- tooth Violet). Bulb slender, 3-5 cm. long ; scape slender ; leaves oblong, taper ing to both ends ; flowers usually only 1, nodding, bright yellow, the segments 2-3 cm. long ; capsule oblong to oval, 2-3 cm.' long. Moist slopes in the mountains. 6. CALOCHORTUS (Mariposa Lily) Herbs from coated corms ; stems slender, branching ; leaves linear ; flowers few, showy, open campanulate, the 3 outer segments green and sepal-like, the 3 inner petaloid, with densely hairy glands ; capsule oblong, obtusely angled. * Anthers obtuse. KEY TO THE SPECIES 11 1. Calochortus Nuttallii T. & G. (Nuttall's Mariposa Lilt). Stem 2-4 dm. high ; leaves few ; flowers 1-5 ; the outer perianth segments lanceolate, shorter than the inner ; the inner obovate-cuneate, white or lilac, with a purple spot above the yellow base, densely hairy around the circular gland ; filaments as long as the sagittate anthers ; capsule acuminate. Moist or dry ground, in the mountains. ♦ « Anthers acute. 2. Calochortus Gunnisoni Wats. (Gunnison's Mariposa Lilt). Very simi- lar but usually smaller ; outer perianth segments scarious margined, inner white or lilac with a yellow base ; gland transverse, oblong or reniform, hairy ; capsule narrowed at both ends. Mostly inflry ground, in the mountains. 7. YUCCA Leaves crowded on the short, thick, woody rootstock, linear, rigid, and dagger-pointed ; flowers large, racemed on the thick scape-like stems, nodding, bell-shaped ; stamens with thick filaments and small versatile anthers'; ovary ses- sile ; capsule large, incompletely 6-celled. 1. Yucca glaaca Nutt. (.Spanish Batonet. Soap-Weed. Bear-Grass). Leaves with numerous thread-like filaments on the margin ; flowers yellowish or greenish-white ; segments thick, ovate, 2-3 cm. long ; fruit erect, large, broadly oblong, somewhat 6-sided ; seeds black and thin. Frequent on dry hillsides. VIII. CONVALLARIACEiE (Lilt-of-the-Valley Family) Herbs with leafy or scapose stems, from true rootstocks ; leaves broad, parallel-veined (in ours) ; perianth segments dis- tinct or united ; styles 1 or 3 ; fruit a fleshy berry. » Flowers racemed. 1. Vagnera. Baceme terminal on a leafy stem. » » Flowers solitary or two together. 2. OispoTain. Peduncles straight. 3. Streptopus. Peduncles bent or twisted near the middle. 1. VAGNERA (False Solomon's Seal) Stems slender, 1-3 dm. high ; leares scale-like below ; inflorescence a terminal raceme or panicle ; flowers small, white or shading to green ; perianth segments similar, spreading ; anthers versatile ; fruit a berry. * Flowers in a raceme. 1. Vagnera stellata (L.) Morong (Star-plowered Solomon's Seal). Stem smooth, 1-4 dm. high ; leaves smooth above, minutely pubescent below, oblong- lanceolate, sessile and somewhat clasping, 3-8 cm. long, usually folded on the mid- rib ; filaments shorter than the perianth ; berry at first green with dark stripes, becoming red when ripe. Tn moist woods and meadows. * * Flowers panicled. 12 KEY TO THE SPECIES 2. Vagnera amplexlcaulis (Nutt.) Greene. Stems 4-8 dm. high ; leaves ovate to broadly lanceolate, clasping at base ; flowers in a small, close panicle ; berry red. Not frequent ; in moist rich woods. 2. DISPORUM The branching stems from slender rootstocks ; leaves alternate, clasping ; flowers terminal, yellowish-white ; perianth of 6 narrow deciduous segments ; stigma 3-cleft ; berry sub-globose. Disporum trachycarpum (Wats.) B. & H. Leaves ovate or narrower, acute ; perianth segments whitish, acute ; ffuit lobed and roughened. Shaded woody slopes. 3. STREPTOPUS Stem stout, with forking and divergent branches ; leaves ovate, acuminate, thin, clasping ; flowers small, the peduncles slender and twisted near the middle. 1. Streptopus amplexifolius (L.) DC. Stems 6-10 dm. high ; the thin smooth leaves glaucous below ; peduncles 1-2-flowered ; anthers tapering to a slender point ; stigma entire, truncate ; berry oval. In moist woods. IX. IRIDACEiE (Ieis Family) Perennial herbs ; leaves linear, 2-ranked, equitant, sheath- ing ; flowers perfect, the 6 perianth segments petal-like ; sta- mens 3, with extrorse anthers ; style 3-cleft at the apex ; ovary inferior, 3-celled, becoming a triangular pod with many seeds. 1. IRIS (Ibis. Flag) Tall herbs from thick rootstocks, with sword-shaped leaves and large showy flowers ; the perianth segments united below into a tube ; the 3 outer ones (sepals) reflexed and larger than the 3 erect inner (petals) ; divisions of the style petal-like, arching over the 3 long stamens. (There are many handsome species in cul- tivation.) 1. Iris Missouriensis Nutt. (Western BLns Flas). Stem slender, the leaves few, mostly basal, shorter than the stem ; flowers 1-3, with scarious dilated bracts, light blue ; parts of the flower 5-7 cm. long ; capsule oblong, obtusely angled, 2-3 cm. long. Common on wet lands. X. ORCHIDACEiE (Orchis Family) Herbs with alternate leaves, very irregular and often showy flowers, 3 petal-like sepals, 3 petals (the lower one different from the others and called the lip), a central column composed of blended stamens and style, and an inferior 1-celled ovary KEY TO THE SPECIES 13 becoming a pod with innumerable very minute seeds. (See Plant Structures, p. 249, also Figs. 235-237 ; also Plant Rela- tions, p. 127, Fig. 123, also Figs. 137-142.) » With tufted fibrous roots. 1. Cypripedlum. The lip a large inflated sac. * * With fascicled fleshy roots. 2. L.iinnorchls. Stem leafy : flower spike not twisted. 3. Gyrostachys. Stem leafy below only ; flower spike twisted. * * * Bulb-bearing. 4. Calypso. Stem naked, a single basal leaf. 1. CYPRIPEDIUM (Lady-slipper) Herbs with large many-nerved leaves sheathing at base, solitary or few large and showy flowers, spreading sepals, usually narrow petals, lip a large inflated sac, and a declined column. 1. Cyprlpedium parviflorum Salisb. (Small Lady-slippee). Stems 3-5 dm. high ; leaves oval to lanceolate, 4-13 cm. long ; sepals and petals longer than the bright yellow lip, which is marked with purple stripes or blotches, flattened from above, 2-3 cm. long. In bogs and damp woods. Bare. 3. LIMNORCHIS Leafy plants, with fleshy roots ; flowers white or greenish in a long spike ; sepals and petals spreading, the lip entire ; column short ; glands naked. 1. JLimnorchis viridiflora (Cham.) Rydb. (Green Orchis). Stem stout and leafy, 2-4 dm. high ; leaves lanceolate, obtusish or acute ; spike crowded, 6-13 cm. long ; flowers small, greenish, the lip lanceolate ; ovary more or less twisted. In bogs and wet woods. 3. GYROSTACHYS (Lady Tresses) Herbs, leafy below, from fleshy roots ; flowers small, spirally 3-ranked ; lip dilated, embracing the column, imdulate or crisped at apex ; capsule erect. 1. Gyrostachys strlcta Bydb. (Hooded Ladv Tresses). Stems naked above, 1-3 dm. high ; leaves smooth, narrowly oblanoeolate or oblong'; spike 5-10 cm. long ; bracts shorter than the white fragrant flowers ; oblong lip thin and veined. 4. CALYPSO Lowbulbous herb, with a single thin ovate leaf, a short naked stem bearing a large arid showy (variegated purple, pink and yellow) flower, nearly similar spreading pointed sepals and petals, a sac-shaped inflated lip larger than the rest of the flower, and a broadly winged petal-like column. Calypso bulbosa (L.) Oakes (Calypso). Bulb solid, with ooralloid roots ; the low scape sheathed by 3-3 loose scales ; leaf ovate, subcordate ; Hp woolly- hairy inside. Moist spruce and pine woods. 14 KEY TO THE SPECIES XL SALICACEiE (Willow Family) Dioecious trees or shrubs, with alternate undivided leaves, flowers in aments and destitute of floral envelopes ; stamens 3-30 ; ovary 1-celled ; and fruit a pod containing numerous seeds with long silky down (" cotton "). (See Plant Structures, p. 255.) 1. Salix. Bracts of the ament entire ; stamens few ; buds with a single scale. 2. Fopulus. Bracts of the ament out-lobed at apex ; stamens numerous ; buds scaly. 1. SALIX (Willow) Trees or shrubs, generally growing along streams, with lithe branches and mostly with long pointed leaves ; the staminate ament with 2-5 stamens to each bract ; the pistillate ament with 1 slender pointed ovary to each bract, becoming a 2-valved capsule. (See Plant Structures, p. 219, Fig. 196, and p. 257, Fig. 240.) * Stamens 2. -t- Leaves broadly linear ; capsule glabrous at maturity. 1. Salix fluviatilis Nutt. (Sandbar or River-bank Willow). A shrub often in dense clumps, 1-3 m. high ; the branches or young shoots very slender ; leaves sparsely denticulate, pubescent only when young, 4-7 cm. long, 5-7 mm. wide ; aments on short leafy branches ; capsule ovoid-conic. Common on the banks of rivers' and on the borders of the smaller streams. -»- ■»- Leaves lanceolate or broader \ capsule silky. 2. Salix Nuttallii Sargent (Nuttall^s Willow). A slender shrub, often spreading from the root and forming dense clumps, 1-2 m. high ; bark on young branchlets distinctly yellowish ; leaves oblong to obovate, from acute to broadly obtuse, glabrous and dark green above, lighter and pubescent below ; aments expanding in early spring before the leaves,'; capsule on a short pedicel, white- tomentose, tapering to a beak. 3. Salix Bebbiana Sargent (Bebb's Willow). A shrub or small bushy tree, 2-5 m. high, not spreading from the root, though often branched from the base ; leaves elliptic to lanceolate, acute, entire or nearly so, puberulent above, pale and tomentose beneath ; aments expanding with the leaves ; capsule long, taper- pointed, on a slender pedicel half as long as the capsule. * » Stamens 3-5. 4. Salix amygdaloldes Anders. (Peach-leaf Willow). Becoming a small tree ; leaves lanceolate or broader, 5-9 cm. long, serrate, taper-pointed, pubescent when young only; aments appearing with the leaves ; capsule ovoid, glabrous, becoming as long as the fllitorm pedicel. 3. POPULUS (Cottonwood. Aspen) Trees with leaves from lanceolate to broadly deltoid, the buds with resinous- aromatic scales ; staminate flowers 1 to each bract, with 8-30 or more stamens ; pistillate flowers also single in the axils of the bracts of the ament, with 2-4 elon- gated styles. KEY TO THE SPECIES 15 * Petiole flattened laterally; leaves broadly ovate or deltoid. 1. Populus treiuuloides Michx. (Aspen. American Aspen). A small tree, 6-20 m. high, usually in dense groves and rarely attaiuiug the maximum size ; bark smooth, green isb.- white ; leaves small, roundish heart-shaped, with a short sharp point and small regular teeth, smooth on both sides, with downy mar- gins ; petioles slender, flattened laterally, causing movement of the leaves in the lightest breeze; lobes of the bracts linear, silky; stamens 6-20; capsule conic. Very common on moist slopes and valleys in the bills and mountains. 2. Populus deltoid.es Marsh. (Cottonwood. Necklace Poplar). The largest of the cottonwoods, 1 m. or more in diameter and 20-30 m. in height, with thick rough furrowed bark ; branches angular ; leaves large, broadly deltoid, sometimes heart-shaped, abruptly acuminate ; scales lacerate ; capsule ovate. On stream banks. (See Plant Relations^ p. 70, Fig. 61.) * * Petioles sub-terete ; leaves lanceolate. 3. Populus angustifolia James (Narrow-leavbd Cottonwood). Becom- ing a medium-sized tree, with rough furrowed bark, 10-20 m. high, rarely 1 m. in diameter ; leaves mostly narrowly lanceolate, sometimes broader with rounded base, acute or obtusish at apex, finely crenulate the whole length ; petioles not flattened laterally; branches terete ; capsule ovoid. Usually forming groves on bottom lands. 4. Populus acuminata Rydb. (Rydberg's Cottonwood). A tall tree with smooth light-colored bark, taller and slenderer than the preceding ; branches terete ; leaves bright green, smooth, lanceolate or broader, long acuminate, rounded at base, crenulate, petioles slender; capsule ovoid, obtuse. From the Black Hills south_through the Rocky Mountains. Largely planted as a shade-tree. XII. BETULACEiE (Birch Family) Trees or shrubs with alternate simple straight-veined leaves, staminate flowers in elongated aments, fertile flowers in long or short aments, 1-5 sepals or none, 2-8 stamens, and a 2-celled ovary becoming a nut (with or without wings). 1. Betula. Stamens 2 ; fruiting bracts 3-lobed, fruit winged. 2. Alnus. Stamens 4 ; fruiting bracts woody, fruit wingless. 3. Corylus. Stamens 8 ; nut large, bony, enclosed by a ieafy involucre. 1. BETULA (Birch) Trees or shrubs ; bark usually separable in sheets, dotted on the branchlets ; staminate aments long, bearing membranous "flowers with 2 stamens ; pistillate aments short, 2-3 flowers in the axil of each bract, the bracts deciduous with the fruit ; nut small, scale-like, broadly winged. (See Plant Relations, p. "1, Fig. 62.) ♦ A small tree or tree-like shrub. 1. Betula fontinalis Sargent (Rocky MotHfTAiN Birch). Ranging in size from a tree-like shrub to a tree 12 m. or more high, usually slender and freely branched ; bark smooth, dark ; branches gracefully drooping ; leaves thin, broadly ovate, with small gland-tipped teeth ; smooth above, lightly pubescent beneath ; wings of the nutlet as broad as the body. On the banks of streams. 16 KEY TO THE SPECIES * A low shrub growing in clumps. 2. Bekula glandulosa Micbx. (Mountain-bog Birch). A small shrub about 1 m. high, usually occurring in rather dense patches, the twigs glandular- warty ; leaves small, glabrous, crenulate, sub-orbicular or obovate, dark green above, lighter and gland-dotted beneath ; bracts 3-lobed ; nut orbicular-winged. Common in wet sub-alpine parks. 2. ALNUS (Alder) Shrubs or small trees with flowers in terminal aments and developed before the leaves, elongated and drooping staminate aments (3 flowers to each bract, a 3-5 parted calyx and as many stamens), ovoid or oblong pistillate aments (2 or 3 flowers to each fleshy bract, calyx of 4 small scales, and a 2-celled ovary), and a wingless fruit. (See Plant Sti-uctures, p. 257, Fig. 241.) 1. Alnus tenuifolia Nutt. (Paperleaf Alder). A large shrub or small tree, usually several-stemmed from the base ; leaves ovate, with prominent veins, rather large, sharply double-toothed ; aments begin their development the sum- mer preceding the season in which they open and hang naked upon the branches during the winter, opening in the spring before the leaves develop ; fertile aments erect, their scales becoming woody, persistent for a time after the small, com- pressed, scarcely winged nuts have fallen. The common Alder on all the streams of this region. 3. CORYLUS (Hazel-nut) Shrubs with toothed leaves, staminate flowers in drooping cylindrical aments (consisting of 8 stamens), pistillate flowers from scaly buds, each in the axil of a bract, with a pair of lateral bracts which become enlarged in fruit, forming the elongated involucral cup or husk. 1. Corylus rostrata Ait. (Beaked Hazel-nut). A small shrub, 1 m., more or less, in height, usually in clumps or small thickets ; leaves ovate, acute, subcor- date ; the involucre bristly, much prolonged above the ovoid nut, forming a narrow tubular beak. Rare in this range. XIII. FAGACEiE (Beech Familt) Trees with alternate simple leaves, staminate flowers in slen- der aments or small heads, fertile flowers 1 or 2 inclosed in a small cup which becomes hard and more or less surrounds the nut, 4-8-lobed calyx, no petals, and 3-20 stamens. 1. QUERCUS (Oak) Trees with alternate simple leaves, greenish or yellowish staminate flowers in slender aments (with 4-8-lobed calyx and 6-12 stamens), pistillate flowers scattered or somewhat clustered, a nearly 3-celled ovary inclosed fty a scaly involucre, which becomes a hard cup around the base of the nut or acorn. 1. Quercus Gambellii Nutt. (Gambell's White Oak). A shrub 3-5 m. high ; leaves obovate in outline, deeply lobed, green above, downy on lower sur- face ; cup hemispheric ; acorn ovoid, acute or obtusish. KEY TO THE SPECIES 17 XIV. ULMACEiE (Elm Family) Trees with alternate serrate pinnately veined leaves, 4-9- cleft calyx, no petals, 4-9 stamens, 2 styles, and a 1-3-celled ovary becoming a winged or berry-like fruit. 1. CELTIS (Hackberry) Small or large trees with pointed petloled leaves, greenish axillary flowers appearing with the leaves, and fruit fleshy, inclosing a stone (drupe). 1. Celtis occidentalls L. Leaves reticulate, heart-shaped, ovate, or lanceo- late, taper-pointed, sharply serrate ; fruit reddish or yellowish, becoming dark purple, as large as small cherries, sweet, edible. Woods and river banks. Rare in this range. XV. MORACEiE (Mulbekey Family) Trees, shrubs, or herbs (our only native genus an herbaceous vine) ; calyx 5-parted ; petals none ; stamens 5 ; ovary superior, 1-celled. 1. HUMULUS (Hop) A rough twining vine, climbing to a height of several meters ; leaves large, opposite, palmately veined, petloled and stipulate ; flowers dioecious, the staminate panicled, the pistillate in clustered aments ; bracts leafy, each 8-flowered ; akene invested with the enlarged scale -like calyx. 1. Humulus lupulus L. (Hop). Leaves broadly ovate in outline, deeply 3-7-clef t ; the ripe fruits (hops) 2-4 cm. long, sprinkled with yellow resinous grains, as is also the calyx. XVI. SANTALACEiE (Sandalwood Family) Herbs or shrubs ; leaves alternate, without stipules ; flowers perfect, the calyx 3-5-cleft and adherent to the ovary ; stamens as many as the calyx lobes ; fruit a nut-like drupe. 1. COMANDRA (Comandra) Smooth perennial herbs, probably parasitic on the roots of other plants ; leaves pinnl-veined, alternate ; flowers bractless, in terminal umbel-like cymes ; calyx bell-shaped ; fruit globose, surmounted by the persistent calyx. 1. Comandra pallida A. DC. (Pale Cohandra). Erect, 1-2 dm. high, the stems arising from horizontal rootstocks ; leaves pale and glaucous, linear to lanceolate or oblong ; cymes corymbose, several-flowered ; calyx greenish-white or purplish ; fruit becoming dry and hard, 5-7 mm. in diameter. Abundant on sandy open or partly wooded slopes and in the draws. IS KEY TO THE SPECIES XVII. POLYGONACEiE (Buckwheat Family) Herbs with alternate entire leaves, stipules in the form of sheaths above the swollen joints of the stem or wanting, 3-6- cleft calyx, no petals, 4-8 stamens, and a 1-celled ovary usually becoming a 3-angled nut-like fruit (achene). » Ochrea none ; flowers subtended by involucres. 1. Eriogonum. Stamens 9 ; calyx 6-cleft or parted. * * Ochrea present ; flowers not involucrate. 2. Rumex. Stamens 6 ; calyx 6-partRd. 3. Polygonum. Stamens 8 ; calyx 5-parted. 1. ERIOGONUM Annual or perennial herbs or with shrubby base, with entire leaves, small flowers in umbellate or capitate clusters which are subtended by a 5-8-toothed or cleft involucre ; style 3-parted ; stigma capitate ; achene 3-angled. * Flowers yellow ; involucre turbinate. -r- Achene angled (not wingedj. 1. Eriogonum umbellatum Torr. (Sulphur Flower). Perennial, with scapose stems ; leaves smooth and green above, white-tomentose below, oblanceo- late or Rpatulate ; bracts large and leaf-like ; umbel of 2-10 rays; flowers glabrous, sulphur yellow. Abundant on hillsides and mountain foothills. 2. Eriogonum subalpinum Greene (Sub-alpine Eriogonum). Very simi- lar to the above, but often larger, 3-5 dm. high ; the leaves more tomentuse above, and the flowers a light yellow or creamy-white. In similar situations. 3. Eriogonum flavum Nutt. (Yellow Eriogonum). Perennial, white-tomen- tose ; scape naked, about 2 dm. high ; leaves oblanceolate ; bracts rather large ; flowers bright yellow, very silky -pubescent ; filaments villous at base ; acheue vil- lous near the top. Canons and foothills. -K -I- Achene winged. 4. Eriogonum alatum Torr. (Winged Eriogonum). An erect perennial, 5-10 dm. high, branched above, with a stiff pubescence ; leaves nearly linear, the midrib conspicuous below ; inflorescence an open panicle, the' solitary involucres with five erect teeth ; flowers small, yellow ; achene 3-winged. * * Flowers white, shading to pink or purple, -f- Annual. 5. Eriogonum annuum Nutt. (Annual Eriogonum). White-tomentose; stems mostly simple, leafy below, 3-6 dm. high ; leaves oblong or oblanceolate ; bracts small ; inflorescence a di- or trichotomous cyme ; calyx white, the outer fiegments broader than the inner, glabrous, as is also the achene. Common on the dry plains. 6. Eriogonum cerniium Nutt. (Nodding Eriogonum). Nearly glabrous ; leaves radical, oval to orbicular ; the slender naked stem branching diffusely and terminating in trichotomous cymes ; flowers white or rose-colored, on deflexed KEY TO THE SPECIES 19 pedicels, the outer sepals broader than the inner. Sandy slopes and plains ; common. ■I- -i- Perennial. 7. Eriogonum ovalifollum Nutt. (Oval-leaved Ebiooonum). Cespitose ; leaves from the crowns of the much-branched caudex, from orbicular to ovate ; bracts very small ; involucres in a single close head ; flowers yellow. This species is abundant in but few localities, but the following variety is very generally dis- tributed. Var. purpureum (Nutt.) Aven Nelson. Size and habit of the species ; the flowers varying from white through pink to purple. Dry gravelly plains. 2. RUMEX (Dock) Coarse herbs often with large leaves, clusters of small mostly greenish flowers, calyx of 6 sepals (3 outer spreading in fruit, 3 inner larger and somewhat colored, enlarged after flowering, veiny, and closing over the nut-like fruit), 6 stamens, and 3 styles. * Wings much enlarged, without tubercles. 1. Rumex venosus Pursh (Veined Dock). Stems stout, erect, 15-30 cm. high, from running rootstocks ; leaves large, somewhat leathery, ovate to lanceo- late, on short petioles ; panicle short, dense in fruit ; pedicels jointed at middle ; the 3 inner sepals much enlarged in fruit, with conspicuous veined wings, a deep sinus at the base, from reddish to a deep maroon-red, without grain-like tubercles or callosities ; achene with smooth, shining concave faces. * Wings rather small, with tubercles. 2. Rumex salicifolius Weinm. (Willow-leaved Dock). Stems clustered, erect or spreading, 3-6 dm. high ; leaves lanceolate or narrower, tapering to both ends, petioled ; racemes erect or spreading ; pedicels jointed near the base ; wings each bearing an ovoid tubercle on the back ; achene acuminate, with con- cave faces. 3. POLYGONUM (Knotwbed. Smartvceed) Herbs with conspicuous stipules sheathing the prominent joints of the stem, small flowers, a 5-parted often petal-like calyx, 4-9 stamens, 2 or 3 styles, and a triangular or lens-shaped achene. 1. Polygonum aviculare L. (Doorweed). Slender and smooth, mostly prostrate or ascending, leafy throughout ; leaves oblong to lanceolate, acutish ; sheaths 2-lobed or lacerate ; flowers in axillary clusters or in spikes with leafy bracts ; sepals very small, with green and pinkish margins ; stamens 8 (rarely 5) ; styles 3 ; nut dull and minutely granular. Yards and waste places. 2. Polygonum bistortoides Pursh (Mountain Smartweed). Stems 3-5 dm. high, slender ; leaves mostly basal, oblong to linear, the cauline much reduced ; flowers in a dense oblong spike terminating the scapose stem or pedun- cle, white or rose-colored ; stamens and styles exserted ; achene smooth and shin- ing. Frequent in grassy mountain valleys and parks. 20 KEY TO THE SPECIES XVIII. NYCTAGINACEiE (Eour-o'clock Family) Herbs with entire fleshy opposite leaves, the stems with swollen joints ; calyx corolla-like, its persistent base constricted above the 1-celled, 1-seeded ovary and becoming an indurated pericarp (anthocarp). 1. ABRONIA (Abronia) Stems branching, more or less glandular ; peduncles axillary and terminal, bearing a terminal involucrate cluster of several to many flowers ; periantb tube elongated, with a 5-lobed limb. * Annual ; flowers small ; fruit with 3-4 broad wings. 1. Abronia micrantha (Torr.) Chois. (Sand Flower). Prostrate, the ex- tremities of the branches ascending ; leaves ovate to oblong, obtuse ; flowers several, greenish-red or pink : the limb not more than 3-5 mm. broad ; wings of the fruit 3 or 4, broad, membranous, wholly encircling the fruit, emarginate at both ends, beautifully reticulated. * * Perennial ; flowers larger ; fruit with 2-5 narrow wings. 2. Abronia fragrans Nutt. (White Abronia. Snowball). Stems several, spreading, 3-7 dm. long, viscid-pubescent ; leaves ovate, obtuse, paired but differ- ing in size ; peduncle long ; flowers numerous, white, forming a sub-spherical cluster, opening at night and very fragrant ; fruit with narrow leathery wing, which do not close over the summit. Common on sandy plains. XIX. PORTULACACEiE (Pueslane Family) Herbs with, entire fleshy leaves, conspicuous flowers that open only in sunshine or bright daylight : sepals 2 (8 in Lewi- sia), separate or united ; petals usually 5; stamens 3-many; styles 2-8-parted ; capsule 1-celled. 1. Portulaca. Flowers yellow ; stamens 7-20; capsule opening by a lid. 2. I.ewisia. Flowers pink ; stamens numerous ; capsule globose, splitting from the base upward, 3. Claytonia. Flowers white, streaked with rose; stamens 3-5; capsule splitting into 3 pieces. 1. PORTULACA (Purslane) Low herbs, with scattered leaves, sessile flowers, 2-cleft calyx, 5 or 6 ephem- eral petals, 7-12 stamens, a 5- or 6-parted style, and "a globular pod opening by a lid. 1. Portulaca oleracea L. ("Pcssley"). Prostrate and smooth; leaves obovate or wedgef orm : petals pale yellow. Cultivated and waste ground. KEY TO THE SPECIES 21 3. LEWISIA (Bitter-root) Perennial, from thick fleshy roots ; leaves all radical ; petals large and showy. 1. Le-wisia rediviva Pursh (Resurrection Root). Flowers 2-3 dm. broad, terminating a short scape which is jointed above the middle and bears a scarious involucre of 5-7 bracts. Common on stony ridges, especially northward. The " State flower " of Montana. 3. CLAYTONIA (Spring Beauty) Succulent herbs, with opposite leaves, racemose flowers, 2 persistent sepals, 5 petals, and a 3-cleft style. • From large (for the plant) deep-set tubers. 1. Claytonia lanceolata sessilifolia Aven Nelson (Mountain Spring Beauty). A single root-leaf (often wanting), a pair of fleshy, sessile, oblong- lanceolate stem-leaves ; flowers few-several, on a peduncle surpassing the leaves ; sepals subacute; petals spatulate to obovate, entire, pale rose-color with purple veins. Common on moist, rich hillsides. * * Annual, with stolons. 3. Claytonia Chamlssol Ledeb. (Chahisso's Claittonia). Stems weak and slender, decumbent, stoloniferous, rooting at the nodes ; leaves spatulate or oblanceolate, obtuse ; the white flowers racemose, on slender pedicels. In spring bogs and on wet banks. XX. CARYOPHYLLACEiE (Pink Family) Herbs with opposite entire leaves, usually 5 sepals (united or separate), 5 petals, 10 stamens (sometimes fewer), 2-5 styles, and a 1-celled ovary becoming a pod. * Sepals united into a tube or cup ; petals clawed. 1. Agrostemma. Calyx 10-nerved, 5-lobed ; styles 5. 2. Silene. Calyx 6-toothed ; styles 3. 3. Vaccarla. Calyx strongly 5-angled ; styles 2. * Sepals distinct ; petals not clawed. 4. Cerastinm. Sepals, petals, and styles 5 ; petals bifid. 5. Arenarla. Sepals and petals 5 ; styles 3 ; petals entire. 1. AGROSTEMMA (Cockle) Annual herbs with linear-lanceolate leaves, large red flowers terminating axillary peduncles ; calyx narrowed at the throat, with linear foliaceous lobes ; capsule 1-celled. 1. Agrostemma Glthago L. (Corn Cockle). Erect, 3-8 dm. high, covered with long soft hairs ; calyx lobes longer than the broad purple-red petals. A weed in wheat fields ; introduced from Europe. 22 KEY TO THE SPECIES 2. SILENE (Oatchfly) Herbs with solitary or clustered flowers, a 5-toothed calyx, 5 petals with slen- der stalk-like base, 10 stamens, 3 styles, a 1-3-celled ovary, and a pod opening at apex by 3 or 6 teeth. 1. Silene antirrhina L. (Sleepy Oatchfly). A slender, nearly glabrous annual, 3-5 dm. high, glutinous about the upper nodes ; leaves from spatulate below to linear above ; inflorescence an open cyme, the pink flowers on slender pedicels ; calyx narrowly ovoid ; petals obcordate, Common on dry sandy rocky banks and slopes. 3. VACCARIA A smooth glaucous annual herb, with tubular, angled, 5-toothed calyx, 5 petals, 10 stamens, 2 styles, and a pod which splits at summit into 4 teeth, 1. Vaccaria Vaccaria (L.) Britt. (Cow Herb or Cockle). Erect, branching above into the wide-spreading cyme ; leaves ovate to lanceolate, acute at apex and clasping at base, 3-5 cm. long ; flowers small, white or rose color ; calyx inflated in fruit. A common weed in cultivated grounds ; Introduced from Europe. 4. CERASTIUM (Chickweed) Small pubescent herbs with weak stems, terminal cymes, white flowers having 5 sepals, 5 petals, 10 stamens, and 5 styles ; a cylindric capsule opening by 10 teeth. 1. Cerastiuiu occidentale Greene (Western Chickweed). Tufted, with many sterile leafy shoots from the base ; the numerous flowering stems somewhat decumbent, 1-8 dm. long, few-leaved ; leaves broadly linear, acute ; cyme few to several-flowered ; peduncle, pedicels and calyx glandular-pubescent ; sepals sea- rious-margined, acute, about 5 mm. long ; petals and mature capsule about twice as long as the sepals. Common on open slopes and in grassy draws. 5. ARENARIA (Sandwort) Tufted herbs with slender sessile leaves, white flowers in cymes which are either compact (head-like) or more open ; sepals and petals 5 ; styles 3 ; capsule globose or oblong, many-seeded and opening by either 3 or 6 teeth. * Flowers in a close head. 1. Arenaria congesta Nutt. (Congested Sandwort)." Many-stemmed from the crown of a thick tap-root, smooth, 1-2 dm. high ; leaves subulate-linear, pointed, scabrous on the margins ; flowers in 1-3 dense clusters, with large, dilated membranous bracts ; petals nearly twice as long as the sepals. Frequent on open or wooded slopes. * * Flowers in a more open cyme. 2. Arenaria Fendleri Gray (Fendler's Sandwort). Similar to the preced- ing in habit, glandular above, the leaves serrulate- scabrous ; flowers in an open cyme, small ; sepals acuminate, about as long as the 6-7 mm. long, white, obovate petals, scarious-margined ; seeds roughened. Dry open hillsides. 3. Arenaria Hookeri Nutt. (Hooker''s Sandwort). A cespitose peren- nial, the mats usually broad; leaves glabrous, crowded, stiff, awl-shaped and sharp-pointed, 1-3 cm. long ; flowering stems short (5-10 cm.), pubescent ; cyme crowded ; bracts linear-lanceolate, with ciliate margins, exceeding the similar sepals ; petals twice as long as the sepals. Frequent on barren stony hills and plains. KEY TO THE SPECIES 23 ' XXI. RANUNCULACE^ (Crowfoot Family) Herbs with flower parts all distinct, 3-15 sepals, petals 3-15 or wanting, numerous stamens or rarely few, and many or few pistils becoming either pods, achenes, or berries. (See Plant Structures, p. 259.) When the petals are wanting the calyx is often colored like a corolla. * Fruit a follicle with several ovules. ^- Flowers regular. 1. Caltha. Leaves simple; petals none; sepals petal-like, 7-13; follicles several, forming a head. 2. Aquilegia. Leaves compound ; petals 5, produced backward into a hollow spur ; follicles 5. ^- ^- Flowers irregular. 3. Delphinium. Leaves palmately cleft or divided ; petals 4, the upper spurred and projecting backward into the spur of the upper one of the 5 petal-like sepals ; follicles many-seeded. 4. Aconltum. Leaves palmately lobed ; petals 3, covered by the upper sepal, which is arched into a hood or helmet ; follicles 3-5. * * Fruit an achene. •*- Petals none or inconspicuous ; sepals petal-like. 5. Anemone. Flowers subtended by an involucre; sepals indefinite; achenes tailless. 6. Pulsatilla. Flowers subtended by an involucre; sepals 5-7; achenes with long feathery tails. 7. Clematis. Involucres wanting ; sepals 4, valvate ; achenes tailed. 8. Atragene. Like Clematis ; the sepals very large ; small petals present. ^- ^- Sepals and petals both present. 9. Ranunculus. Petals yellow, with a nectariferous pit at the base; achenes compressed ; leaves simple. 10. Batrachinm. Petals white ; achenes transversely wrinkled ; leaves dis- sected. 11. Cyrtorhyncha. Petals yellow, narrow; achenes terete; leaves compound. 12. Oxygraphis. Petals yellow; achenes longitudinally striate; leaves simple, ere n ate. 1. CALTHA (Marsh Maeigold) Smooth herbs with round or oblong leaves with cordate base ; sepals large, showy, early deciduous ; stamens numerous : follicles many-seeded. 1. Caltha rotundifolia (Huth.) Greene (Elk Slip). Leaves radical, rather thick, with narrow basal sinus, entire or dentate ; scapes 1-15 cm. high, one flow- ered • sepals oblong-obovate, white or bluish on the outside. Abundant in wet aub-afpine parks. 3. AQUILEGIA (Columbine) Herbs with ternately compound leaves, lobed leaflets, large showy flowers ter- minating the branches, 5 sepals colored like the petals, 6 petals with short spread- 24 KEY TO THE SPECIES ing lip and produced backward into large hollow spurs much longer than the calyx, numerous stamens, and 5 pistils becoming erect follicles. 1. Aquilegia cserulea James (Blue Columbine). Glabrous, a-8 dm, high; leaves mostly radical, glaucous below, the leaflets lobed ; flowers large, varying from blue to white ; the spurs long and slender. This beautiful plant is the " State flower" of Colorado, and is said by gardeners to be the handsomest Columbine in the world. It is abundant in moist woods in the mountains. 2. Aquilegia chrysantha Gray (Yellow Columbine). Taller and more slender, with peduncles often pubescent ; flowers bright yellow, the spurs very slender. Wet ravines in mountains ; Colorado and southward. 3. DELPHINIUM (Larkspur) Herbs with palmately divided leaves, flowers in terminal racemes, 5 petal-like sepals (the upper one prolonged into a spur at the base), 4 petals (the upper pair continued backward into long spurs inclosed in the calyx spur), numerous stamens, and 3 pistils becoming many-seeded pods. (See Plant Structures, p. 260, Fig. 244.) 1. Delpbinium scopulorum Gray (Mountain Larkspur). Tall, 1 m. more or less, branching above ; leaves 5-7-parted, each lobe again cleft or parted, the divisions from lanceolate to narrowly linear ; inflorescence minutely ciuereous- pubescent ; flowers blue ; ovaries minutely pubescent. Moist open woods, 2. Delphinium Geyeri Greene (Geyer's Larkspur. Poison-weed). A tufted perennial with numerous thick flbrous-woody roots, canescently tomentose, 3-6 dm. high ; root-leaves numerous, stem-leaves few (especially upward), all cleft into many linear divisions ; flowers in a strict raceme, blue, with a stoutish spur. Common on the plains, where the dense tufts of root-leaves appear in early spring, offering a tempting mouthful to hungry cattle ; sometimes eaten with fatal results. 3. Delphinium Nelsonii Greene (Nelson's Larkspur). Perennial from a. cluster of tuberous roots ; stem slender, nearly simple, 1-3 dm. high, finely pubes- cent ; leaves cleft into broadly linear divisions ; flowers blue, somewhat pubescent, the lower petal 2-clef t, with a tuft of hair near the middle. Common in the loose soil of draws in the foothills. 4. ACONITUM (Monkshood) Erect perennial herbs with showy flowers ; sepals 5, petal-like ; stamens numerous. 1. Aconitum Columbianum Nutt. (Mountain Monkshood). Stem 1 m. or more high, pubescent above, with short viscid hairs ; leaves large, the lobes toothed or cut ; flowers purple, in a loose raceme. Moist open woods. 5. ANEMONE (Anemone) Erect perennial herbs ; radical leaves petioled, lobed or parted ; those of the stem forming an involucre ; stamens numerous ; achenes compressed, pointed . 1. Anemone Canadensis L. (Canada Anemone). Somewhat pubescent; leaves large, 5-7-cleft, and the lobes more or less toothed : those of the involucres similar but sessile ; flowers solitary, on bifurcate peduncles with secondary invo- lucres ; sepals large and white ; achenes flat, nearly glabrous, in globose heads. Common on the banks of streams. KEY TO THE SPECIES 25 2. Anemone globosa Nutt. (Round-feuited Anemone). Stems slender, 1-3 dm. high, silky, as are also the leaves, which are dissected into narrow lobes ; flowers 1 or more ; the sepals red or dull crimson, 6-10 mm. long ; the oblique, pointed, densely woolly achenes in a globose head. 6. PULSATILLA (Pasque Ploweb) Perennial herbs, from thick semi-woody roots, densely soft hairy throughout ; stems scapose and 1-flowered ; sepals petal-like ; stamens very numerous and the achenes with long feathery tails. 1. Pulsatilla hirsutlssima (Pursh) Britt. (American Pasque Flower). Leaves all radical, dissected, the divisions narrow ; stems naked but for the dis- sected involucre, which is some distance below the single large flower, the blossoms opening before the leaves appear ; sepals large, ovate-oblong, purplish, varying to nearly white. In early spring, in moist canons and on wooded slopes. 7. CLEMATIS (Virgin's Bower) Perennial herbs or semi-woody climbers with opposite, petioled, pinnately compound or parted leaves ; the genus is easily recognized by Its 4 valvate sepals and the long-tailed achenes. 1. Clematis llgustlcifolia Nutt. (Western Virgin's Bower). Stem climb- ing, more or less woody ; leaves mostly pinnately 5-foliate, the leaflets incisely toothed or trifld, nearly glabrous ; the white flowers in leafy panicles ; sepals equaling the stamens. Clambering over bushes on creek banks. 3. Clematis Douglasii Hook. (Douglas's Clematis). An erect, tufted, somewhat villous herb, 3-6 dm. high ; leaves pinnatifld, the divisions linear or linear-lanceolate ; sepals 3-4 cm. long, thick, deep purple within, paler on the out- side, valvate, only the villous tips spreading ; achenes silky, with tails 8-3 cm. long. Moist slopes in open woods. 8. ATRAGENE (Virgin's Bower) Climbing vines much like Clematis ; of the numerous stamens, a few of the outer ones have the fliaments broadened (petal-like); sepals large and showy; the long styles plumose 1, Atragene Americana Sims (Purple Virgin's Bower). Leaves trifo- liate, with thin, ovate, acute leaflets ; the four large sepals widely spreading, thin, strongly veined, and pubescent on the veins and margins. Moist wooded hillsides. 9. RANUNCULUS (Buttercup) Herbs with alternate leaves, solitary or clustered yellow (sometimes white) flowers, 5 sepals, 5 (rarely more) flat petals, numerous stamens, and numerous pistils becoming a head of mostly flattened and pointed achenes. (See Plant Structures, p. 222, Fig. 202.) » Radical leaves undivided ; low (mostly less than 15 cm.). 1. Banunculus elllpticus Greene (Bright-faced Buttercup). Stems 5-10 cm. high, 1-several-flowered ; leaves smooth ; the root-leaves entire, mostly elliptic ; the stem-leaves few, generally 3-cleft to about the middle ; flowers large, 18-25 mm. across ; the petals twice as long as the sepals, bright yellow, glossy 3 26 KEY TO THE SPECIES and shining ; achenes with a short beak. Moist hillsides and draws. Very early spring. 2. Ranunculus inamoenus Greene (Homely Buttercup). Taller, at length 20 cm. or more high, sparsely pubescent ; root-leaves broadly oval, crenately toothed at summit, on petioles 2-3 times as long as the blade ; stem-leaves sessile, ternately divided into oblanceolate segments ; petals 5, obovate-oblong, about 5 mm. long ; achenes pubescent, in a small ovoid head. Moist parks and valleys. * * Leaves all cleft or parted ; tall (20-30 or more cm. high). 3. Ranunculus acriformis Gray (Wyoming Buttercup). Tall and slender, often 3 or more dm. high, pubescent ; leaves all 3-5-parted, the segments 2-3-clef t into linear divisions ; petals broadly obovate, 5-7 mm. long ; achenes with a broad curved-hook beak shorter than the body. Common in wet meadows and on grassy stream banks. 4. Ranunculus Macounii Britt. (Macoun'^s Buttercup), Stems coarse, 2-6 dm. high, with spreading branches, the whole plant rather roughly hairy; leaves large, 3-divided to the base, the ovate divisions (leaflets) variously parted and cleft into acute segments]; petals about 5 mm. long ; achenes in a sub-globose head, with a short pointed beak. 5. Ranunculus eremogenes Greene. A light-green, very glabrous plant, with thick or swollen hollow stems, 1-2 dm. high ; leaves 5-parted and the seg- ments lobed, the lobes toothed ; petals light yellow, longer than the sepals ; the numerous achenes in an oblong head, small, smooth, and nearly beakless, falling from the receptacle when dry. Very common in the margins of spring bogs and ponds. 10. BATRACHIUM (Water- crowfoot) Perennial aquatic herbs, with finely dissected leaves and white flowers ; other- wise nearly as in Ranunculus. 1. Batrachium trichopliyllum (Chaix) Bossch. (White Water-crow- poot). Submerged ; stems slender ; leaves petioled, the segments linear ; flowers on stout peduncles, blooming at the surface of the water ; achenes beakless. In ponds and sluggish streams, 11. CYRTORHYNCHA Characters nearly those of Ranunculus ; the long-petioled blpinnately divided or compound leaves, the narrowly spatulate petals, and the longitudinally ribbed, thin-walled, slightly inflated achenes will serve to distinguish it. 1. Cyrtorhyncha ranunculina Nutt. (Nuttall's Buttercup). Tufted, with many slender stems and long-petioled root-leaves, 1-2 dm. high ; leaflets with oblong or linear lobes; sepals yellowish, almost as long as the petals ; achenes in a globular head, oblong-cylindric, tipped with the incurved style. 12. OXYGRAPHIS Much like Ranunculus, but the stems scape-like, the achenes flattened and longitudinally striate on the faces, 1, Oxygraphis Cymbalaria (Pursh) Prantl. (Seaside Crowfoot). Small, mostly less than 1 dm. high, spreading by runners which root at the nodes ; leaves mostly basal, oval with cordate base : flowers 1-5 ; the petals 5-9 ; achenes in an oblong head, tipped with a sharp point. Common on wet alkaline flats and ditch banks. KEY TO THE SPECIES 27 XXII. BERBERIDACEiE (Baebekrt Family) Low shrubs with alternate compound leaves without stip- ules ; sepals 6, petals 6, and the 6 sensitive stamens opposite them ;■ the anthers open at the top by uplifted valves ; the single pistil becomes a 1-3-seeded berry. 1. BERBERIS (Barbebkt) Shrubs with yellow wood and yellow flowers in dense racemes ; the style short and the stigma peltate. 1. Berberis Aqulfolium Pursh (Trail;ng Baeberry. Oregon Grapb). Low, mostly creeping among rocks or on stony slopes ; the leaves evergreen ; leaflets 3-7, ovate, acute, spiny-toothed ; racemes terminal ; the berries blue or purple. XXIII. PAPAVERACEiE (Poppy Family) Herbs with alternate leaves, 3 ephemeral or scale-like sepals, 4-6 petals, 6 to many stamens (opening lengthwise), and a single pistil ; the fruit a 1-celled pod or capsule. 1. Argemone. Stem spiny ; sap yellow ; leaves glaucous. a. l^nomegra. Stem spiny and densely hispid ; sap milky ; leaf not glaucous. 3. Capnoides. Stems smooth ; sap watery ; leaves decompound and glau- cescent. 1. ARGEMONE Spiny branching herbs, with sessile, lobed, spiny-toothed leaves, which are glaucous and more or less blotched with white ; flowers large and showy, with 2-3 sepals bearing a horn-like spine near the tip ; capsule spiny, opening by several valves at summit. 1. Argemone intermedia Sweet. (Spiny Poppy). Tall, often 1 m. high, freely branching ; flowers white, 6-9 cm. broad ; the petals broadly obovate. Common on sandy plains. 3. ENOMEGRA Characters much like those of Argemone, but the stem and leaves densely bristly and less spiny ; the leaves a dull green with some puberulenoe and slightly if at all glaucous ; sap thick, milky-white. 1. Enomegra liispida (Gray) Aven Nelson (Htspid Poppy). Erect, branch- ing, 4-8 dm. high ; sepals hispid on the horn-like tip ; petals white, obovate, about 3 era. long ; capsule armed with stout, hispid spines. Frequent on sandy slopes and valleys. 3. CAPNOIDES Pale leafy-stemmed herbs, with compound dissected leaves and racemes of yellow flowers ; 8 small sepals and 4 connivent petals (1 of the outer is spurred 28 KEY TO THE SPECIES and the 3 inner are keeled), all early deciduous ; stamens 6, in 2 sets, opposite the outer petals ; capsule linear. 1. Capnoides aureum (Willd.) Kuntze (Golden Capnoides). Tufted, the many leafy stems spreading ; leaves dissected, the segments oblong or cuueate ; flowers golden yellow, the spur shorter than the rest of the flower ; pod spreading or drooping, distinctly torulose ; the seeds black and shining or obscurely reticu- lated. Sandy or stony draws and banks. 3. Capnoides montanum (Engelm.) Britt. (Mountain Capnoides). Very similar but with lighter green, more finely dissected foliage ; the pods ascending or erect, terete and not torulose. This species is the more frequent in the south- ern part of our range and the preceding northward and eastward. XXIV. CRUCIFERiE (Mustard Family) Herbs, usually pungent, with alternate leaves, terminal clusters of flowers, 4 sepals, 4 petals, 6 stamens (4 long and 2 short), and a 2-celled pod. (See Plant Structures, p. 261, Fig. 346.) * Flowers white. -I- Silique flattened contrary to the partition, short (less than 8 mm.). 3. Thlaspi. Petals conspicuous ; silique obovate, with keeled and obscurely wing-margined sides. 9. Bursa. Petals small ; silique obcordate-cuneate, not winged. 3. Hepidiiim. Petals either inconspicuous or evident; silique much com- pressed, orbicular or elliptic. -*- -(- Silique linear ; seeds in 1 row, about 2 cm. long. 6. Cardamine. Petals large ; silique erect, with a short thick style. * * Flowers yellow. +■ Silique globose to oblong, short (not more than 8 mm.). 10. Draba. Silique oblong, flattened parallel to the partition. 8. Xesquerella. Silique globose or ellipsoidal, stellate-pubescent. 7. Physaria. Silique didymous, the cells globose-inflated, stellate-pubescent. ■»- 4- Silique on a long stipe, linear, 3 cm. or more long. 1. Stanleya. Silique flattened, with an evident mid-nerve. •I- -I- -i- Silique terete, from linear oblong to long linear. 5. Borlpa. Silique linear-oblong, 9-18 mm. long leaves pinnatifid. 4. Sisymbrium. Silique linear, 3-5 cm. long. -*-■*--*--»- Silique 4-angled, linear, 2-8 cm. long. 11. Clieirantlius. Petals long-clawed, with a flat blade. 1. STANLEYA Perennials with large roots and large glaucous pinnatifid leaves ; flowers in long naked terminal racemes of yellow flowers. KEY TO THE SPECIES 29 1. Stanleya pinnata (Pursh) Britt. (Stanleya). Stems 5-10 dm. high ; leaves from nearly entire to deeply pinnatifld ; sepals linear, the petals with a long claw ; filaments exserted ; sillques ^3 times as long as the style. 2. LEPIDIUM (Peppbr-geass) Herbaceous plants with entire, toothed or pinnatifld leaves and mostly small white flowers. 1. Lepidium ramosissimum Aven Nelson (Branched Fepper-orass). Freely branched from the base up, 2-4 dm. high ; leaves pinnately toothed ; petals small, spatulate, half as long as the sepals ; the fruiting racemes long and numer- ous ; siliques ovate with a broad shallow sinus. Waste grounds and open stony plains. 2. Lepidiuxn montanum Nutt. (Large-flowered Lepidium). Stems sev- eral, 1-8 dm. long, loosely spreading ; leaves pinnatifld ; flowers conspicuous, white or yellowish-white ; siliques elliptical, with a shallow notch and au evident style. Frequent on alkaline flats. 3. THLASPI (Penny Cress) Small perennials with mostly entire leaves, conspicuous white flowers, and ob- cuneate siliques. 1. Thiaspi Coloradense Eydb. (Colorado Candytuft). The stems few to many from the crown of a tap-root, 5-10 cm. long ; root-leaves rosulate, elliptic or broader, petioled ; stem-leaves ovate, sessile by an auricled base ; the silique about 6 mm. long, obscurely retuse. Moist draws in the foothills. 4. SISYMBRIUM Slender perennial herbs, glabrous, with nearly entire linear-oblanceolate leaves. 1. Sisymbrium linifolium Nutt. (Mountain Mustard). Glabrous and glaucous, 3-5 dm. high, with several slender simple stems ; leaves thick ; flowers light yellow ; siliques divaricate, on short pedicels ; seeds in 1 row. Frequent on sandy plains and slopes. 5. RORIPA (Cress) Perennial herbs from rhizomes, with sinuate pinnatifld leaves ; flowers with spreading sepals and conspicuous petals. 1. Roripa sinuata (Nutt.) A. S. Hitch. (Spreading Cress). Stems several, spreading-prostrate, 1-3 dm. long; leaves oblong-lanceolate in outline, mostly deeply pinnatifld ; siliques acute at both ends, often curved, beaked by a slender style. Abundant in wet, waste grounds and on saline flats. 2. Roripa Nasturtium (L.) Rusby (True Water-Cress). Stems spreading and rooting; leaves with 3-11 roundish or oblong nearly entire leaflets; petals white, twice the length of the calyx ; pods linear, ascending on slender widely spreading stalks. Cultivated from Europe, but escaped Into brooks and ditches, 6. CARDAMINE (Bitter Cress) Erect glabrous plants, growing along streams, with rather large white flowers; the leaves lobed or lyrately pinnate ; siliques flattened, mostly linear. 30 KEY TO THE SPECIES 1. Cardaiuine vallicola Greene (Greek-bank Cress). Stems clustered, 2-4 dm. high, rather stout ; leaves green with a few scattered hairs on the margins, deeply lyrate-pinnatiftd, the leaflets 5-9, the terminal one large; siliques erect on ascending pedicels, linear, tapering to the style. 7. PHYSARIA (Bladder-pod) Low perennial herbs, with entire leaves ; the yellow flowers in terminal racemes, and the silique membranous-inflated, the two cavities sub-globose. 1. Physaria didymocarpa (Hook.) Gray (Double Bladder-pod). Stel- lately pubescent throughout, the several stems and numerous root-leaves crowded on the crown ; leaves broadly spatulate or obovate ; flowers large ; siliques deeply emarginate above and below. 8. LESQUERELLA (Bladder-pod) Low herbs much like Physaria except as to the silique. which is globose or ellipsoidal and much smaller. 1. I^esquerella argentea (Pursh) MacM. (Silvery Bladder-pod). Stel- late-pubescent throughout ; stems several, slender ; leaves linear or narrowly oblanceolate, 3-6 cm. long ; the yellow flowers conspicuous, with petals 5-6 mm. long; pedicels 1-3 cm. long, in fruit recurved ; silique globose or nearly so, with a slender style as long as the silique. Common on sandy plains. 2. Lesquerella montana (Gray) Wats. (Mountain Bladder-pod). Re- sembling the preceding ; root-leaves from oblanceolate to broadly obovate, peti- oled ; siliques elliptical, 5-6 mm, long, equaled by the slender style, erect, on widely spreading, curved pedicels. Stony slopes and hilltops. 3. L