Field Key to the /• Mora or Yellowstone National Park by Don G. Despain Proceeds from booklets sold by the Yellowstone Library and Museum Association help the National Park Service program of information and education at Yellowstone Cover picture courtesy of National Park Service Field Key to the /• Mora or Yellowstone National Par by Don G. Despain Published by YELLOWSTONE LIBRARY AND MUSEUM ASSOCIATION in cooperation with NATIONAL PARK SERVICE U.S. DEPARTMENT OF THE INTERIOR TABLE OF CONTENTS Forward iii Plant Names v Plant Parts vii Plant Keys xii References xiv Glossary xv Index to families xxxii Key 1 Index and Common Names 225 LIST OF FIGURES Fig. 1. Typical Flower x Fig. 2. Grass Flower x Fig. 3. Inflorescences xi Fig. 4. Leaf Structure xi Fig. A. Fern Structure xxix Fig. B. Legume Flower Structure xxix Fig. C. Roots xxix Fig. D. Shapes of Sympetalous Corollas xxx Fig. E. Ovary Positions xxx Fig. F. Composite Flower xxx Fig. G. Types of Pubescence xxxi Fig. H. Terms Relating to Leaves xxxi 1975 Yellowstone Library and Museum Association FOREWORD On a wall in my home hangs a framed specimen of Allium textile Nels . & Macbr . This specimen gained such prominence more from the limitations of married student budgets than for its graceful beauty. My wife needed a picture to frame for a class she was taking, and we couldn't afford a picture worthy of both the money and effort that would go into such a project. A search through my embry- onic collection of pressed plants produced one of proper size and line. Since then A . textile has graced a wall in each of our many homes . Just after we came to Yellowstone in late 1971 John Stockert, a naturalist with a botanical bent, brought a specimen to me for identification. I immediately recognized it as A. textile. No such species was listed in the key then in use for the park, nor was there a specimen under that name in the herbarium. John assured me that plants like his specimen were quite common around Mammoth Hot Springs so I checked published keys and descriptions and verified my first determination . A thorough evaluation of both the key and the herbarium in 1973 indicated a revision of both was in order. Eventually all sheets of the Yellowstone Herbarium were sent to the University of Wyoming, where I checked the determinations against the holdings of the Rocky Mountain Herbarium. This effort revealed a few first records for the park, one first record for Wyoming, and brought to light the existence of several other species in the park's herbarium that had masqueraded under other names, including three specimens of A^ textile . An excellent regional flora, The Vascular Plants of the Pacific Northwest (Hitchcock et al. 1955-1969) now summarizes the nomenclature of plants of the area border- ing Yellowstone National Park and the nomenclature of the park flora has been updated. With these changes and additions it seemed advisable to construct a new manual . The first section of this book contains basic botanical information that will help beginning students better under- stand the uses and peculiarities of plant taxonomy. This is iii followed by the keys which were, for the most part, con- densed from other works. Species included are those represented in the Yellowstone Herbarium or are shown on spot maps for Wyoming collections at the Rocky Mountain Herbarium. The keys do not include many species which occur around Yellowstone Park but have not been collected within its boundaries . If you should find a species in the park which is not included in this key, make a collection and send a duplicate to the Yellowstone Herbarium . But remember, A COLLECTING PERMIT IS REQUIRED to collect specimens within Yellowstone Park. Be considerate of both the plant population and the visiting public . Hopefully this book will be of use to those seriously interested in botany and plant names: the serious amateur botanist, beginning botany students, and researchers working in Yellowstone. For those interested in a simpler treatment a very fine book with color photographs arranged by flower colors , Flowers of Yellowstone and Grand Teton National Parks (Shaw 1974), is available. The keys in this book are a condensation of those from other authors. The key for Salix was condensed from The Willows of Montana (Dorn 1970); for Carex from Manual of the Carices of the Rocky Mountains and Colorado Basin (Hermann 1970); for Cirsium from A Biosystematic Study of Cirsium (Compositae) in Wyoming (Gardner 1972) The rest of the keys come from Vascular Plants of the Pacific Northwest (Hitchcock, Cronquist, Ownbey and Thompson 1955-1969) . I have modified the keys slightly and worked in species we have that were not treated in the other works. However, I take full responsibility for errors encountered in this work. My appreciation goes to John Stockert whose interest in our flora rekindled my taxonomic interests, and to Judy O'Neale who did most of the typing and made comments on the manuscript and to Don Shute who did a meticulous job of proofreading. I also thank Dr. John Reeder, curator of the Rocky Mountain Herbarium, for space in and the use of that herbarium. He, Mrs. Reeder, and Bob Dorn were of much assistance. I also owe Dr. C. L. Porter for teaching me herbarium techniques and the fundamentals of plant taxonomy. iv PLANT NAMES A common complaint about botanists is that their field is very esoteric . Why must they call the common dandelion Taraxacum officianalis and argue about whether a cotton- wood tree should be called Populus balsamifera or Populus tricocarpa? My sister once heard that "pigweeds" were good to eat. She got a book about common weeds, looked up pigweed, compared the picture in the book with the weeds in our garden, cooked a potful, tasted them, and pronounced them barely fit for consumption. She had collected plants belong- ing to the genus Amaranthus . The pigweed which is a delicious green is a member of the genus Chenopodium . Because "pigweed" encompasses so many unrelated species, communication using that name is difficult and confused. Chenopodium refers to a specific group of related plants. The scientific or Latin name of a plant unlocks all the experiences and knowledge acquired and recorded by others regarding that species of plant. Without any name you are reduced to only your own experiences. The more precise the definition employed, the more useful the term as a container of information. Although Latin names may be difficult to pronounce and remember, many of the common names applied to plants come from Old English and are just as strange to us . I have often identified a yellow flower for nonbotanical friends by its common name, groundsel, only to have them ask what the common name is . We have also adapted many Latin names as common names. Geranium, rhododendron, and gailardia are quite familiar to us . We feel more at home in a community where we know most peoples' names and some of their background and relationships . Th same applies to the natural communities around us . For this reason I have included the common name following the Latin name in the index. There are problems with Latin names too. Early collectors sometimes named plants which, unknown to them, had already been named. A choice then had to be made as to which name was to be used. Botanists have agreed upon a set of rules known as the International Rules of Botanical Nomenclature. These rules reduce confusion and help to keep the definition of a species name fairly- precise. Occasionally someone discovers that the name of a plant known and used for a long time is invalid and must be supplanted by another . Thus Douglas-fir, known as Pseudotsuga taxifolia for many years and memorized by countless forestry students, must now be called Pseudotsuga menziesii according to the Rules. Sometimes taxonomists disagree on what should be called a species and be worthy of a separate specific name. A species is commonly defined as a population of organisms reproductively isolated from other populations . Unfortunately, there are a few cases where it is difficult to apply this definition. In the genus Lupinus is a group of species that apparently at one time were reproductively isolated and morphologically dissimilar. Some of the normally sterile hybrids became polyploid (acquired multiple sets of the normal number of chromosomes) and were thus able to reproduce. These now fertile hybrids were able to cross with the parent species, producing morphological variation grading among several species. What this group or member of this group is called becomes a matter of opinion which varies between taxonomic "splitters" and "lumpers". There will always be need for taxonomists and revisions . For a more extensive discussion of plant names read How Plants Get Their Names (Bailey 1963) . PLANT PARTS The seemingly infinite variety of combinations of plant parts and the ways in which they are modified and ornamented provides a means of distinguishing species. Describing this variation requires precisely defined terms which are usually unfamiliar to nonbotanists . Technical plant descriptions resemble a foreign language. There are new terms such as inflorescence , and redefined words (like "fruit") which have a precise botanical meaning different from the definition used by menu planners. Once these new terms are mastered it is possible to use them to follow a key to the plant name and compare a written species description with the plant in hand to see if they are the same . Seed bearing plants normally consist of roots, stems, leaves, and flowers. Characteristics of the flowers are used for classification purposes. It is assumed that flowers, which are present during only a small portion of the life of the plants, are less subject to modifying stresses than are the vegetative parts. However, vegetative parts are useful to distinguish individual species and often used in keys. Flowers Flowers are primarily reproductive organs housing the pollen producing androecium and the egg and seed producing gynoecium (Fig. 1). The pollen is produced in a sac termed an anther ususally supported by a fillament. Together these form a stamen. The egg is contained in an ovule which is housed in an ovary. A structure called a stigma receives the pollen and provides entry for a tube produced by the pollen. This tube grows until it contacts the egg and releases the sperm nuclei into the egg cell, accomplishing fertiliza- tion. There is often a structure between the stigma and the ovary called a style. These three structures com- prise the pistil. The ovary matures or ripens into the fruit. Flowers with both stamens and pistils are called perfect; those with only stamens (staminate flowers) or pistils (pistilate flowers) are imperfect. Most flowers also have several auxiliary structures . Most conspicuous are the brightly colored petals which attract pollinators . The petals of a flower collectively vii are called the corolla. The corolla may have separate petals (polypetalous) or the petals may be united (sympetalous or gamopetalous) . Less conspicuous, smaller, and usually greenish in color are the sepals, collectively known as the calyx. These too may be separate or united. All of these structures arise from the receptable. Flowers are modified in various ways. Some parts may be lacking or greatly reduced. The parts are often altered in shape and may have various ornamentations such as hairs, glands, or other structures. These alterations usually aid the species in adapting to specific pollinating agents . This is especially apparent in the orchid family where the petals often are shaped like the reproductive parts of certain insects. The flowers of the grass family are so greatly modified that a special terminology is used. The basic unit is a floret diagramed in expanded view in Fig. 2. These are grouped together into spikelets . The spikelets are then arranged into various inflorescences. The calyx and corolla are reduced to the minute lodicules but the essential organs are well developed. The main protective envelope (palea, lemma and glumes) are modified bracts from the inflorescence. The First Book of Grasses (Chase 1959) would be well worth reading for those interested in this fascinating group of plants. The arrangement of flowers on a stem is called an inflorescence . The names of the parts and various types of inflorescences are given in Fig. 3. The development of these different types can be envisioned as a gradual reduction in the length of the pedicels and peduncle starting with a panicle and ending with a head. Stems Plants usually have stems that bear leaves and flowers. If the stems are elongated with leaves spread out along the stem the plant is called caulescent. If the stem is just a mass of tissue at the soil surface with the leaves all bunched together (basal) it is called acaulescent. Sometimes stems are modified to aid in vegetative reproduction. An example is the runners on strawberries . These are known as stolons. If stems grow underground they are called rhizomes. Sometimes the stems swell underground and store starch. These are called tubers (ex. potato). The eyes on a potato are buds on the stem. The places viii on the stem where the leaves and buds originate are called nodes (Fig. 4) and the stem tissue between nodes is the internode. The stems of many perennial species die back to the soil surface each year and originate again in the spring from a structure called a caudex. Annuals, biennials, and perennials can be distinguished by examining the plant between the root and stem for evidence of previous year's leaves. Perennials will have several sets of old leaves or leaf bases and biennials only one set. Annuals, of course, will have none from the previous year although there may be remnants of leaves that were produced early in the spring and have since died. Leaves Leaves are the main sites of photosynthesis, the food-making process. They are also the structures where oxygen and carbon dioxide are exchanged with the atmos- phere and water is lost to the air . Leaves usually consist of a stem called a petiole and a blade (Fig. 5). At the base of the leaf where the petiole attaches to the stem of the plant there is always a bud. There may also be some smaller leaflike struc- tures called stipules. If only one leaf arises from a node the leaf arrangement is alternate; if two leaves arise opposite each other at each node the arrangement is opposite. Sometimes more than two leaves arise from each node. This is called a whorled arrangement. Leaves are often greatly modified. The blades are shaped variously. The blade margin is either smooth (entire) or variously indented (toothed or lobed) . The blade itself may be subdivided into leaflets in which case the leaf is compound as opposed to simple. The leaflets are arranged palmately or pinnately. The leaves and stems are usually ornamented with hairs (pubescence) . These hairs vary in both shape and amount . If plants have no hairs they are termed glabrous . Diagrams of variations pertaining to leaves are found on Page xxxi --as part of the glossary. ix xi PLANT KEYS Keys are used to unlock something--in this case, to determine the name of a plant about which you may be curious. This is done by making a series of choices, deciding whether your specimen fits this description or that. This is a dichoto- mous key, meaning that only two choices are given at a time and the plant should fit one of the two . Each of the two choices has the same number in the key. Thus, if your plant does not fit the first number 1, then it should fit the second. You decide which it fits best. This is an indented key which means that the next two choices are indented under the one you have just made. You will find keys highly stylized and at first a little difficult, but as you gain more practice you will begin to appreciate the style and learn to let it work for you. Always read both choices. If you are not familiar with the terminology, don't guess--look it up in the glossary. With difficult choices, follow both to see which takes you to the most logical end point. The sequence of families follows that of Hitchcock et al . (1955-1969) . Within the families genera are arranged alphabetically. In those instances where we have only one species in a genus, family, or even higher level, that species will be listed where it keys out at the highest level. Thus some species names will be found in the key to genera of a family, some in the key to families, etc. This should cause no difficulty with the combined checklist-index for those looking to see if a particular species is treated in the key. The number following the families in the key to the families refers to the page on which the key to the genera of that family are found . A word of caution. Because this key was made from a checklist of collected specimens in two herbaria only, you may find a plant not yet listed. In that case it could easily key out to an erroneous name, especially if it is closely related to one in the key. Also there are a number of plants that have been collected around Yellowstone but not in the park itself. These do not appear in the key, so be careful. There are several regional keys for surrounding areas whichyou may also want to consult. See Vascular Plants of the Pacific Northwest by Hitchcock et al. (1955-1969); Flora of Montana by Booth and Wright (1959); Flora of xii Idaho by Davis (1952); Manual of the Plants of Colorado by Harrington (1954) . REFERENCES Bailey, L. H. , 1963. How plants get their names. Dover Publications Inc. , New York. 181 p. (First published 1933 by Macmillian Co. New York.) Booth, W. E. , 1950. Flora of Montana. Part I. Conifers and Monocots. The Research Foundation at Montana State College, Bozeman, MT. 232 p. Booth, W. E. and J. C. Wright, 1959. Flora of Montana Part II . Dicotyledons. The Research Foundation at Montana State College, Bozeman, MT. 280 p. Davis, R. J., 1952. Flora of Idaho . Wm . C. Brown Co., Dubuque . 828 p . Dorn, R. D. , 1970. The Willows of Montana. The Herbarium Dept. of Bot. and Microbiol., Mont. St. Univ., Bozeman, MT. 18 p. Gardner, R. C, 1972. A biosystematic study of Cirsium (Compositae) in Wyoming . MS. thesis. Univ. ofWyo. 119 p. Harrington, H. D. , 1954. Manual of the plants of Colorado. Sage Books, Denver. 666 p . Hermann, F. J. , 1970. Manual of the Carices of the Rocky Mountains and Colorado Basin. Agriculture Handbook No. 374. U .S .D .A . For . Ser . 397 p. Hitchcock, C. L. and A . Cronquist, 1973. Flora of the Pacific Northwest. Univ. Wash. Press, Seattle. 730 p. Hitchcock, C. L., A. Cronquist, M. Ownbey, and J. Thompson, 1955-69. Vascular Plants of the Pacific Northwest (5 vols.). Univ. Wash. Press, Seattle. Porter, C. L., 1959. Taxonomy of Flowering Plants W . H . Freeman & Co . , San Francisco . 452 p. Shaw, R. J. , 1975. Plants of Yellowstone and Grand Teton National Parks. Wheelwright Press Ltd. Salt Lake City. 159 p. GLOSSARY Abaxial. On the side away from the axis. Fig. 4 Acaulescent. Without a stem, but may have a scape. Accrescent. Increasing in size with age. Acerose. Needle-shaped or with a needle-like tip. Achene. Type of fruit that is indehiscent, dry with a tight thin pericarp. Acicular. Needle-shaped. Acuminate. Gradually and concavely tapered to a narrow tip or sharp point. Fig. H Acute. Sharp-pointed. Fig. H Adaxial. On the side toward the axis. Fig. 4 Adnate. Grown together or attached. Adventitious. Introduced but not naturalized. Alternate. With leaves arising singly at the node; with stamens rising between petals. Fig. 4 Alveolate. Honeycombed. Ament. Dense, braceate spike or raceme with a non- fleshy axis bearing numerous small, naked or apetalous flowers; catkin. Fig. 3 Amplexicaul. Clasping the stem. Ampliate. Enlarged, dilated. Anastomosing. Rejoining to form a network. Androecium . The stamens, collectively. Fig. 1 Androgynous. Having both staminate and pistillate flowers, the staminate above the pistillate. Annual. A plant which germinates flowers and seeds in a single season. Annular. Ring shaped or marked transversely by rings. Anther. Pollen bearing part of stamen . Fig. 1 Anthesis . The period during which a flower is fully expanded . Anthocyanin. Water-soluble pigments ranging from blue or violet through purple to crimson. Apiculate. Ending abruptly in a small usually sharp point. Apiculus. Small usually sharp point. Appendiculate . Appendage bearing. Appressed. Pressed flat against another organ. Arachnoid. With cobwebby, usually sparse pubescence of relatively long, soft, tangled hairs. Arborescent. Treelike. Arcuate . Curved into an arc . Aristate. Tipped with an awn or bristle. XV Articulate. Jointed. Ascending. Growing obliquely upwards. Attenuate. Tapering very gradually to a very slender tip; more extreme than acute or acuminate. Fig. H Auriculate. Having auricles (small projecting lobes or appendages) . Awn. Slender, usually terminal bristle. Axil . The point of the angle formed by the leaf or petiole with the stem . Fig . 4 Axillary. Located in or arising from an axil. Baccate. Berrylike and pulpy. Banner. The upper, generally enlarged petal of a leguminous flower . Fig . B Barbellate. Diminutive of barbed . Fig. F Basafixed. Attached by the base. Basiscopic . Toward the basal end. Bi~. A prefix meaning two or double. Biennial . Completing its life history in two years . Bifid. Two parted. Bifurcate. Two forked. Bilabiate. Two-lipped. Blade . The expanded portion of a leaf or petal . Bract. A specialized leaf from the axil of which a flower arises; a more or less reduced or modified leaf in an inflorescence. Fig. 3. Bracteate. With bract. Bracteole, bractlet. Diminutive of bract. Bulbils . Diminutive of bulb . Caespitose, cespitose. Matted; growing in dense little clumps . Callosity. A thickened raised area usually paler in color Callus. A firm thickening; the firm, thickened base of the lemma in many grasses. Fig. 2. Calyculate. With a set of small bracts around the calyx. Calyx. All the sepals of a flower collectively. Fig. 1. Campanulate. Bell shaped. Fig. D. Canescent. Pale or gray, because of fine, close whitish pubescence . Capillary. Hair-like. Fig. F. Capitate. In a head. Capsule. A dry, dehiscent fruit composed of more than one carpel. Carinate. Keeled. Carpel. The fertile leaf (megasporophyll) of an angiosperm, which bears the ovule. xvi Carpophore. The part of the receptacle which in some kinds of flowers is prolonged between the carpels as a central axis. Caruncle. An appendage near the hilum of certain seeds. Caryopsis. The fruit of grasses , grain. Fig. 2. Caudex . A short, more or less vertical, often woody, persistent stem at or just beneath the surface of the ground, serving as the perennating organ. Caudiciferous . Caudex bearing. Caulescent. With an obvious, leafy stem that has obvious internodes . Cauline . On or pertaining to the stem. Chartaceous. Papery in texture. Chaff. Dry, thin, scales. Chlorophyllous . Continaing chlorophyll. Ciliate. With a fringe of marginal hairs; with scattered long hairs . Fig . G . Ciliolate . Diminutive of ciliate. Cinereous. Ashy in color usually because of a covering of short hairs. Cirrhose. Tendril-like. Clavate . Club shaped. Fig. C. Claw. The narrow, petiole-like base of some sepals and petals. Cleft. Cut about half way to the midrib or base. Collar. The outer side of a grass leaf at the juncture of the blade and sheath. Coma. A tuft of hairs, especially on a seed. Compound. Composed of more than one similar organ. Conduplicate . Folded together lengthwise, usually into two equal, more or less appressed halves. Connivent. Converging or coming together. Cordate. Heart shaped with the notch at the base. Fig. H Coriaceous. Leathery in texture . Corniculate . Bearing little horns or crests. Corolla. All the petals of a flower collectively. Fig. 1. Corymb. A racemose inflorescence with the lower pedicles progressively longer than the upper such that the inflores- cence is flat topped. Fig. 3. Corymbiform . Having the form but not necessarily the structure of a corymb. Corymbose. In a corymb. Costa. A prominent rib or vein; in ferns, the midrib or a pinna . XVII Crenate. Provided with rounded teeth. Fig. H. Crested. With an elevated, often complex appendage or rib on the summit or back. Crisped. Irregularly curled or crooked. Crown. The persistent base of an herbaceous perennial; the leafy top of a tree; a circle of appendages in the throat of a corolla. Cruciate. Cross-shaped. Culm. The aerial stem of a grass or sedge. Cucullate. Hooded or hood-shaped. Cuneate . Wedge-shaped or triangular with the narrow end at the point of attachment. Cuspidate. Tipped with a cusp. Cyathiform . Cup shaped. Cyme. A class of inflorescences having the terminal flower bloom first. Cymose. The flowers in a cyme. Deciduous. Falling after completion of the normal function. Decompound. Repeatedly compound into numerous leaflets. Decumbent . With a prostrate or curved base and an erect or ascending tip. Decurrent. With an adnate wing or margin extending down the stem or axis below the point of insertion . Deflexed. Bent downward. Dehiscent. Opening at maturity, releasing or exposing the contents . Deltoid. Shaped like an equilateral triangle, with one of the sides at the base. Fig. H. Dendritic. Branched like a tree. Dentate. With spreading, pointed teeth. Fig. H. Denticulate. Diminutive of dentate. Depauperate. Small or poorly developed. Diadelphous. United in two groups, one of the groups sometimes of a single member . Dichotomous. Forking more or less regularly into two branches of about equal size. Didymous. Developing in pairs. Dimidiate. Halved, as if one half were missing. Dimorphic. Of two forms. Dioecious . With male and female flowers on separate individuals . Diploid. Having two full chromosome complements per cell. Disarticulating. Separating at a pre-existing joint. xviii Disk flowers. Tubular flowers in the center of most composit heads . Fig . F . Distal . Toward the tip or far end . Distinct. Not united with similar organs. Divaricate. Widely spreading from the axis or rachis. Dolabriform . Pick-shaped, attached more or less toward the middle. Fig. G. Dorsal. Pertaining to the back. Dorsiventral . Flattened, with the two flattened sides unlike . E-, ex-. Prefix meaning without. Echinate. Provided with prickles. Elliptic. In the shape of an ellipse. Emarginate. With a small notch at the tip. Entire. Smooth margin, not notched or toothed. Fig. H. Epidermis. Surface layer of cells in leaves. Epigynous. With the perianth and stamens attached to the ovary. Fig. E. Equitant . Astride, as if riding . Erigeroid. Like Erigeron. Erose. With an irregular margin, as if gnawed. Exfoliating . Peeling off in layers . Exserted. Projecting beyond an envelope as stamens from a corolla . Falcate. Sickle-shaped, or curved like a hawk's beak. Farina . Meal-like powder . Farinose. Covered with meal -like powder. Fascicle. A close bundle or cluster. Filament. The stalk of a stamen . Fig. 1. Filiform. Very slender, threadlike. Fimbriate. Fringed. Fistulous. Hollow. Flabellate. Fan-shaped. Floccose. Covered with very long, soft, fine, loosely spreading and more or less tangled hairs. Floret. An individual flower of a definite cluster as in the head of a composite or spikelet of grass. Fig. 2. Floriferous . Flower bearing . Foliaceous. Leafy in texture. -foliolate . Suffix indicating the number of leaflets in a compound leaf. Follicle. A dry fruit composed of a single carpel which at maturity splits along the ventral (seed bearing) suture only. XIX Fornix. One of a set of small scales or appendages in th tube or throat of the corolla of some kinds of plants. Frond. The "leaf" of a fern. Fig. A. Furcate. Forked. Fuscous. Gray-brown. Fusiform. Spindle shaped; thickest near the middle and tapering to both ends . Galea. The strongly concave or helmet-like upper lip of certain bilabiate flowers. Gamopetalous . Petals united at least near the base. Gamosepalous . Sepals united at least near the base. Geniculate. Abruptly bent or twisted. Gibbous. Abruptly swollen on one side commonly near the base. Glabrate. Nearly glabrous. Glabrescent. Becoming nearly or quite glabrous. Glabrous. Smooth, without hairs or glands. Gland. An organ on the surface which produces a sticky or greasy viscous substance. Glandular. Provided with glands. Fig. G. Globose. More or less spherical. Glochidiate. Barbed at the tip. Glomerate. Densely compacted in clusters or heads. Glomerule. A small, compact, headlike cyme; any dense small cluster. Glume. One of the pair of bracts, found at the base of a grass spikelet, which do not subtend flowers. Fig. 2 Glutinous. Sticky. Gynaecandrous . Having both staminate and pistillate flowers , the staminate below the pistillate . Gynobase . An enlargement or prolongation of the receptacle of some flowers. Gynoecium . The carpels of a flower , collectively. Fig. 1. Hastate. Shaped like an arrowhead, but with the basal lobes more divergent. Fig. H. Head. An inflorescence of sessile or subsessile flowers crowded together at the tip of a peduncle. Fig. 3. Helicoid cyme. A sympodial cyme with the apparent main axis curved in more or less of a helix, because the successive lateral branches which make up the axis all arise on the same side. Herbaceous. Leaflike in color or texture, or not woody. Hermaprodite . With both sexes together in the same individual, or in the same flower. XX Hirsute. Pubescent with rather coarse or stiff but not pungent, often bent or curved hairs; coarser than villous, but less firm and sharp than hispid. Hispid. Pubescent with coarse and firm, often pungent hairs . Hypanthium . A ring or cup around the ovary usually formed by the union of the lower parts of the calyx, corolla and androecium. Hypogynous. With perianth and stamens attached directly to the receptacle. Fig. E. Imbricate. Arranged in a tight spiral so that the outer- most member has both edges exposed and at least the innermost member has both edges covered. Imparipinnate . Pinnately compound leaf with a single terminal leaflet. Incised. Rather deeply and sharply cut. Incumbent. Cotyledous with the back of one of them against the radicle. Indehiscent. Remaining closed at maturity. Inferior ovary. One with the other flower parts attached to a hypanthium which is adnate to the ovary and projects beyond it . Fig . E . Inflorescence. A floral cluster of a plant or the arrangement of the flowers on the axis. Infra-. A prefix meaning beneath. Internode. The tissue between nodes on a stem. Fig. 4. Introrse. Turned down toward the inside or facing inward. Involucel. Diminutive of involucre, an involucre of the second order . Involucre. A set of bracts beneath an inflorescence. Fig. F Keel. A sharp or conspicuous longitudinal ridge; also the two partly united lower petals of many Leguminosae Fig. B. Lacerate. Torn, or with an irregularly jagged margin. Laciniate. Cut into narrow and usually jagged margin. Laminar. Thin and flat. Lanate. Woolly. Lanceolate. Lance-shaped. Fig. H. Lemma . One of the pair of bracts which subtend the individual flowers in grass spikelets. Fig. 2. Lenticular. Shaped like a double-convex lens. Lepidote. Covered with small scales. Ligulate. Having a ligule. In the composites a ligulate head is composed of only ligulate flowers. XXI Ligule. The flattened part of the ray corolla in the Compositae (Fig. F.) and to the inner side of the leaf at the junction of blade and sheath in many grasses and some sedges . Linear . Narrow with nearly parallel sides . Fig . H . Locule. A seed cavity (chamber) in an ovary or fruit. Fig. 1. Lodicule. One of the tiny scales which may represent a vestigial perianth in grasses. Fig. 2. Lunate. Cresent-shaped . Malpighiaceous . Dolabriform. Marcescent. Withering and persistent, as petals and stamens in some kinds of flowers . Medifixed. Attached near the middle. Megaspores . A spore which gives rise to a female gametophyte. Membranous. Thin and flexible, like a membrane. Mephitic . Bad smelling . Mericarp . An individual carpel of a schizocarp. -merous. A suffix referring to the parts in each circle of floral organs, usually with a numerical prefix. Mesophyte. A plant adapted to growth under ordinary moisture conditions . Monadelphous stamens. Stamens with the filaments or anthers connected. Moniliform. Constricted at regular intervals. Monocephalous . With a single head. Montane. Pertaining to the mountains. Mucronate. Tipped with a short, sharp, slender point. Fig. H. Multicipital . Many headed. Muricate. With small, sharp projections. Nectary. A structure which produces nectar. Node. A place on a stem where a leaf attaches. Fig. 4. Nodose. Knobby, used especially in describing roots. Nutlet. A very thick walled achene; one of the dry, indehiscent, one-seeded half-carpels of the Boragin- aceae or Labiatae . Ob-. A prefix meaning in a reverse direction. Obsolete. So much reduced as to be scarcely detectable or entirely suppressed. Obtuse. Blunt, with the sides coming together at an angle of more than 90 degrees. Fig. H. Ochroleucous . Yellowish white. xxii Opposite. Two leaves situated directly across from each other at a node . Fig. 4. Orbicular. Circular in outline. Orifice. Opening or mouth. Ovary. The structure containing the ovules . Fig. 1. Ovate. Shaped like a long section through a hen's egg (applied to plane surfaces). Fig. H. Ovoid. Shaped like a hen's egg (applied to solid O objects . ) Ovule. A young or undeveloped seed. Fig. 1. Palea. One of the pair of bracts which subtend the flowers in grass spikelets. Fig. 2. Palmate. With three or more lobes; nerves, leaflets, or branches arising from a common point . Panicle. A branched inflorescence . Fig. 3. Paniculate. Adjectival form of panicle. Paniculiform . Of the form of a panicle. Pannose. Felt-like. Papillae. Short rounded, blunt proj ections . Papillate, papillose. Covered with pappillae . Pappus. Modified calyx crowning the achene of the Compositae. Fig. F. Parietal placenta. A placenta along the walls or on the intruded part of a compound unilocular ovary. Pectinate. Comb-like, with a single row of narrow spreading appendages or hairs . Pedate. Fan-like. Pedicel. The stalk of a single flower in an inflorescence. Fig. 1. Pedicellate. With a pedicel. Peduncle. The stalk of an inflorescence or of a solitary flower . Peltate. Attached by the lower surface instead of by the base or margin. Pendulous. Hanging or drooping. Penicillate. With a tuft of short hairs at the end. Perfoliate. With the stem passing through the leaf. Perianth. All the sepals and petals of a flower, collectively. Pericarp. The wall of the fruit. Perigynium . A special bract which encloses the achene of Carex. Perigynous. With perianth and stamens united into a basal saucer or cup (hypanthium) distinct from the ovary. Fig. E. xxiii Persistent. Remaining attached after completing its function . Petal. A member of the second set of floral leaves, generally colored or white and serving to attract pollinators. Fig. 1. Petaloid. Petal-like. Petiole. A leaf stalk. Petrophilous . Living on rocks. Phyllary. An involucral bract of the Compositae. Pilose. With long, straight, soft, spreading hairs. Pinna . One of the primary divisions of a pinnately compound leaf of frond. Fig. A. Pinnate. With two rows of lateral branches or appendages or parts along an axis . Pinnatifid. More or less deeply cut in pannate fashion. Pinnatilobate . With pinnately arranged lobes. Pistil. The female organ of a flower, composed of 1-more carpels, ordinarily differentiated into ovary, style, stigma. Fig. 1. Placenta. The tissue to which ovules are attached. Plumose. Feathery. Fig. F. Polypetalous . Petals separate from each other. Polysepalous . Sepals separate from each other. Puberulent. Minutely pubescent; with fine, short, loose, curled hairs. Fig. G. Pubescent. Bearing hairs (trichomes) of any sort. Pulverulent. Covered with a powder. Pulvinate. Cushion-like. Puncticulate . Diminutive of punctate. Pungent. Firmly sharp pointed; or sharp or acrid odor. Pyriform . Pear shaped. Raceme. A more or less elongated inflorescence with pedicles arising from the bottom upward on an unbranched axis. Fig. 3. Racemiform . Having the form of a raceme. Rachilla. Diminutive of rachis; the axis of the spikelet in the grasses and some sedges. Fig. 2. Rachis. A main axis, such as that of a compound leaf. Radiate. In the Compositae, having ray flowers only along the margin of the head. Ray. The ligule or ligulate flower in the Compositae (Fig . F . ) , or one of the branches of an umbel . Receptacle. The end of the stem to which the other flower parts are attached. Fig. F., Fig. 1. xxiv Reflexed. Bent backward . Reniform . Kidney-shaped. Repent. Creeping. Replum . A persistent, septum-like or frame-like placenta which bears ovules on the margins, as in the Cruciferae . Reticula. Plural of reticulum--network . Reticulate. Forming a network, as the veins of a leaf. Retrorse. Directed backward or downward. Refuse . With a small terminal notch in an otherwise rounded tip. Fig. H. Revolute. With the margins rolled or turned under. Rhizomatous. Bearing rhizomes. Rhizome. Creeping underground stem. Rhombic. Having the shape of a rhombus— an equilateral parallelogram with oblique angles . Rosulate. In rosettes. Rotate. Saucer-shaped. Fig. D. Rotund. Round or rounded. Rufous. Brownish- or yellowish-red. Rugulose . Diminutive of rugose (wrinkled). Runcinate. Sharply cleft or pinnatifid with backward- pointing segments. Saccate. Furnished with or in the shape of a sac or pouch Sagittate. Arrowshaped. Fig. H. Salverform. With a slender tube and an abruptly spreadin limb . Fig . D . Saprophyte. Living on dead organic matter. Scaberulous. Diminutive of scabrous. Scabrid. Roughened. Fig. G. Scabridulous . Minutely roughened . Scabrous. Rough to the touch, due to the structure of the epidermis or to the presence of short, stiff hairs. Scandent. Climbing. Scape. A leafless peduncle arising from ground level in acaulescent plants. Scapose. With the flowers on a scape. Scarious. Thin, dry, and chaffy in texture and not green Scorpioid cyme. A sympodial cyme with a zigzag rachis, the successive lateral branches which make up the rachis arising on different sides . Scrotiform. Shaped like a scrotum. Scurfy. Covered with very small dry scales. Secund. With the flowers or branches all on one side of the axis . XXV Septa. Plural of septum. Septate. Having partitions. Septum. A partition; in an ovary, a partition formed by the connate walls of adjacent carpels. Seriate. In a series. Sericeous. Silky from the presence of long soft more or less appressed hairs. Fig. G. Serrate. Toothed along the margin with sharp, forward pointing teeth. Fig. H. Serrulate. Diminutive of serrate . Fig. H. Sessile. Attached directly by the base. Seta. A bristle. Setose. With bristles . Setulose. Diminutive of setose . Sheath. An organ which partly or wholly surrounds another organ. Silicle. A fruit like a silique, but short, not much longer than wide . Silique. An elongate capsule in which the two valves are deciduous from the persistent seed-bearing partition called the replum. Sinuate. With a strongly wavy margin. Sinus. Cleft or recess between two lobes or segments of an expanded organ such as a leaf. Sorus. A cluster of sporangia . Fig. A. Spatulate. Shaped like a spatula, rounded above and narrowed to the base. Fig. H. Spicate. Arranged in a spike. Spiciform . With the form of a spike . Spicules. Tiny sharp projections. Spike. An elongate inflorescence with sessile or subsessile flowers. Fig. 3. Spikelet. A group of flowers of the grass family usually subtended by a set of glumes. Fig. 2. Spinulose. With a small spine at the tip. Sporangium. A case or container for spores. Fig. A. Spur . A hollow appendage of the corolla or calyx usually functioning as a nectary. Squarrose. Abruptly spreading or recurved at some point above the base. Stamen. The male organ of a flower consisting of a filament and anther. Fig. 1. Staminode. A modified stamen which does not produce pollen . xxvi Stellate. Star-shaped; hairs having several to many- branches from the base. Fig. G. Sterile. Unproductive or infertile. Stigma. The part of the pistil which is receptive to pollen. Fig. 1. Stipe. The stalk of a structure without regard to its mor- phological nature. Stipitate. Borne on a stipe. Stipulate. Having stipules . Stipule. One of a pair of basal appendages found on many- leaves . Stolon. An elongate, creeping stem on the surface of the ground . Stoloniferous . Bearing stolons . Stolonous. Stolon-like. Stomate . A special opening in epidermal tissue for the exchange of gasses. Striate. Marked with fine, more or less parallel lines. Strigillose. Diminutive of strigose . Strigose. With straight, appressed hairs all pointing in more or less the same direction. Strophiole. An appendage at the hilum in certain seeds. Style. The slender stalk separating the stigma from the ovary. Fig. 1. Stylopodium . An enlargement or disklike expansion at the base of the style. Sub-. Prefix, meaning under or almost. Subtend. To be directly below and close to. Subulate. Awl-shaped. Sulcate. Marked with longitudinal grooves. Superior. Hypogynous. Suture. A seam or line of fusion. Sympodial. With the apparent main axis actually consisting of a series of short axillary branches. Tepal. A sepal or petal, or member of an undifferentiated group . Terete. Cylindrical; round in cross-section. Ternate. In threes. Tetrads. A group of four. Thallus. A plant body which is not clearly differentiated into roots, stems and leaves. Thyrse. An elongate, narrow, mixed panicle, consisting of a series of racemosely arranged small cymes. Tomentose. Covered with tangled or matted, wooly hairs. Fig. G. xxvii To men turn . A covering of tangled or matted hairs. Torulose. Diminutive of torose--alternately contracted and expanded . Trifid. Divided into three parts. Trifoliate; trifoliolate . With 3 leaves; with 3 leaflets. Trigonous. With 3 angles. Truncate. With the apex (or base) transversely straight or nearly so; as if cut off. Tuber. A thickened part of a rhizome ususally used for food storage. Tubercle. A small swelling or projection. Tuberculate. Having tubercles . Tuberous. Thickened like a tuber. Turbinate. Top-shaped. Turion . A small bulblike offset . Umbel. A racemose inflorescence with a vary short axis and more elongate pedicels which seem to arise from a common point. Fig. 3. Uncinate. Hooked at the tip. Uni-. Prefix meaning one. Urceolate. Urn-shaped or pitcherlike, contracted at or just below the mouth. Fig. D. Valvate. Arranged with the margins of the petals (or sepals) adjacent throughout their length, without overlapping; opening by valves. Valve. One of the portions of the ovary wall into which a capsule separates at maturity. Ventricose. Inflated or swelling out on one side only or unequally. Vernal. Pertaining to the spring season. Verticil. A whorl of leaves or flowers. Verticillate . Arranged in verticils. Verucose. Warty; covered with wartlike projections . Vestigial. Much reduced and hardly or not at all functional. Villous. With long, soft often bent or curved but not matted hairs . Viscid. Sticky or greasy. Whorl. A ring of 3 or more similar structures radiating from a node or common point. Fig. 4. Wing. A thin flat extension or projection from the side or tip of a structure; one of the two lateral petals of a legume flower. Fig. B. Xerophytic . Adapted to like in dry places. xxviii XXIX XXX XXXI INDEX TO FAMILIES Aceraceae 14 Adoxaceae 24 Alismataceae 5 Amaranth. 105 Anacardi. 154 Apocyn. 170 Asclepiad. 18 Berberid. 12 Betulaceae 95 Boragin. 175 Cactaceae 157 Callitrich. 12 Campanul. 192 Capparid. 22 Caprifoli. 190 Caryophyll. 107 Ceratophyll. 11 Chenopodi. 101 Compositae 193 Convolvul . 33 Cornaceae 165 Crassul. 131 Cruciferae 119 Cupress. 38 Cyperaceae 45 Droseraceae 6 Elaeagn . 157 Elatinaceae 12 Equisetaceae 35 Ericaceae 165 Euphorbi. 153 Fumariaceae 119 Gentian. 169 Geraniaceae 153 Gramineae 55 Grossulari. 136 Haloragid. 11 Hippurid. 11 Hydrocharit. 5 Hydrophyll. 174 Hyperic . 154 Iridaceae 85 Isoetaceae 35 Juncaceae 42 Juncagin. 40 Labiatae 178 Leguminosae 143 Lemnaceae 82 Lentibulari . 188 Liliaceae 82 Limnanth. 24 Linaceae 31 Loasaceae 156 Loranthaceae 96 Lycopodi. 1 Malvaceae 154 Menyanth. 11 Nyctagin. 26 Nymphaceae 11 Onagraceae 157 Ophiogloss . 2 Orchidaceae 86 Orobanch. 187 Paeoniaceae 23 Pinaceae 38 Plantagin. 188 Polemoni . 171 Polygalaceae 21 Polygonaceae 97 Polypodi. 36 Portulac. 105 Potamogeton . 40 Primulaceae 168 Ranuncul . Ill Rhamnaceae 154 Rosaceae 137 Rubiaceae 189 Salicaceae 89 Santalaceae 28 Saxifrag. 132 Scrophulari. 180 Selaginaceae 1 Solanaceae 180 Spargani. 81 Typhaceae 81 Umbellifer. 160 Urticaceae 96 Valerian. 192 Verbenaceae 19 Violaceae 155 Zannichelli. 3 xxxii SYNOPTICAL KEY TO THE DIVISIONS OF VASCULAR PLANTS 1 Plants not producing seeds; spores the typical dissemi- nules 2 Leaves always small or very narrow, simple and with a single, unbranched midvein; sporophylls or sporan- giophores often aggregated into a terminal cone 3 Leaves mostly alternate or opposite, distinct; sporangia borne in the axils of vegetative or more or less modified leaves that are often aggregated into a terminal cone; stem not as in the following group LYCOPODIOPHYTA 1 3 Leaves whorled, connate around the stem, only the tips distinct; sporangia borne on highly modified sporangiophores that are aggregated into a characteristic terminal cone; stem longitudinally ribbed and grooved, hollow, jointed, with a per- sistent meristematic region at the base of each internode EQUISETOPHYTA EQUISETACEAE 2 Leaves in most species larger and with a branching vein system, often cleft or compound POLYPODIOPHYTA 2 1 Plants producing seeds; seeds the typical disseminules 4 Ovules naked, not enclosed in an ovary; woody plants PINOPHYTA 2 4 Ovules enclosed in an ovary; herbs and woody plants MAGNOLIOPHYTA 2 Division LYCOPODIOPHYTA 1 Plants homosporus, the spores numerous in each spor- angium, all about alike; leaves without a ligule (Lycopodiatae) LYCOPODIACEAE LYCOPODIUM ANNOTINUM L . 1 Plants heterosporus , the microspores very numerous and tiny, the megaspores much larger and fewer (up to 300); leaves ligulate, i.e., with a small ventral appendage a little above the base (Isoetatae) 2 Leaves small, not more than about 5mm long; stems branched and more or less elongate megaspores 1-4 (Selaginellales ) SELAGINELLACEAE SELAGINELLA DENSA Rydb . I 2 Leaves elongate, generally well over 10mm long; stems very short, unbranched; megaspores numerous commonly 50-300 (Isoetales) ISOETACEAE 35 Division POLYPODIOPHYTA 1 Plants eusporangiate , the sporangia thick-walled, 2- valved, without an annulus, borne in a "fertile spike" which projects from the upper side of the leaf, not form- ing sori, and without an indusium; leaves sometimes bent over in bud, but not circinate (Ophioglossales) OPHIOGLOSSACEAE BOTRYCHIUM MULTIFIDUM (Gmel . ) Trevis . 1 Plants leptosporangiate , the sporangia thin-walled with a definite annulus, usually forming definite sori on the lower surface or along the margins of the leaf, each sorus often subtended by an indusium; leaves circinate in bud (Polypodiales) POLYPODIACEAE 36 Division PINOPHYTA (Gymnospermae) 1 Leaves scale-like or somewhat needle-like, but opposite or whorled; ovulate cones small, woody or often fleshy, the scales few (2-12) opposite or in 3's CUPRESSACEAE 38 1 Leaves needle-like born singly or in small bunches of 2-5; ovulate cones woody, with many scales spirally arranged PINACEAE 38 Division MAGNOLIOPHYTA 1 Embryo mostly with two cotyledons; plants usually with intrafascicular cambium; vascular bundles in herbaceous forms usually borne in a ring which encloses a pith; floral parts, when of definite number, typically borne in sets of 5, less often 4, seldom 3 (carpels often fewer); leaves mostly pinnately or palmately veined; herbs or woody plants, usually with vessels in the stem and leaves as well as in the roots, or a few species wholly without roots MAGNOLIATAE or 6 Dicotyledons 2 1 Embryo with one cotyledon; plants without intrafascicular cambium; vascular bundles often scattered; floral parts, when of definite number, typically borne in sets of 3, seldom 4, never 5 (carpels often fewer); leaves in most species parallel-veined; ours all herbs; vessels often confined to the roots or even wanting LILIATAE or Monocotyledons 3 ARTIFICIAL KEY TO THE FAMILIES OF MAGNOLIOPHYTA LILLIATAE or Monocotyledons 1 Flowers naked or merely subtended by much-modified, usually chaffy or bristle-like bracts 2 Plants floating , thallus-like; flowers apparently con- sisting of 1 or 2 stamens and a naked pistil, borne in small, marginal pockets of the thallus LEMNACEAE 82 2 Plants rooted and (if aquatic) with only the stems and leaves floating 3 Leaves opposite; plants aquatic, submersed or floating ZANNICHELLIACEAE ZANNICHELLIA PALUSTRIS L . 3 Leaves alternate (except sometimes the uppermost) , or plants non-aquatic, or both 4 Leaves terete, basal, the plant acaulescent; pistillate flowers of two types, some borne among the sheaths of the basal leaves and with long styles that may reach to the surface of the water JUNCAGINACEAE 42 4 Leaves usually flattened, the plants caulescent; pistillate flowers (if any) usually all alike 5 Pistils and stamens 4; connective of the anthers broadened and sepal-like; plants with submersed or floating stems and leaves, only the inflores- cence emergent POTAMOGETONACEAE 40 5 Pistils and stamens mostly other than 4; con- nective of the anthers not broadened and sepal- like; plants mostly partially or wholly out of water 6 Flowers largely imperfect, the staminate and pistillate borne separately in heads or in an 3 elongate, terminal spike, the staminate flowers upper- most; plants not grasslike 7 Flowers several in globose-capitate clusters, each subtended by 3-5 chaffy bracts SPARGANIACEAE 81 7 Flowers very numerous in a terminal, terete spike, each naked or subtended merely by slender hairs; fruit neither hardened nor strongly beaked, concealed in the spike by the subtending hairs TYPHACEAE 81 6 Flowers mostly perfect, if imperfect then usually borne in greatly reduced spikes and the staminate flowers often not uppermost; plants grasses or grasslike 8 Leaves in 3 vertical ranks on the often triangular; solid or pithy, not swollen-noded stem; sheaths closed; each flower usually subtended by a single (occasionally 3) bract and often with several inner subtending scales or bristles; ovary sometimes enclosed in a sac-like covering; fruit an achene, usually more or less beaked; styles often 3 CYPERACEAE 45 8 Leaves in 2 vertical ranks on the usually terete, mostly swollen-noded, generally hollow stems; sheaths either open (as commonly) or partially to completely closed; each flower usually subtended by 2 bracts but with no more than 2 (3) inner subtending scales (these usually obscure); ovary never enclosed in a sac; fruit a grain (the ovary wall grown tightly to the seed), rarely at all beaked; styles (in ours) no more than 2 GRAMINEAE 55 1 Flowers with a perianth; perianth segments either all alike or differentiated into a calyx and corolla 9 Plants submersed or floating aquatics, only the inflor- escence emersed; flowers 4-merous, the perianth of one sepal-like series POTAMOGETONACEAE 40 9 Plants mostly terrestrial, if aquatic rarely either emersed or floating, but with other than 4-merous flowers 10 Flowers imperfect, the staminate and pistillate borne separately in capitate-globose clusters, each subtended by 3-5 chaffy bracts; fruit a hardened, beaked achene SPARGANIACEAE 81 10 Flowers perfect or if (as rarely) imperfect the staminate and pistillate not borne separately in 4 capitate-globose clusters and not subtended by 3-5 chaffy bracts; fruit various 11 Plants with usually triangular stems and 3-ranked leaves, grasslike; perianth of several bristles or scales, not in two series of (2) 3 each; fruit a lenti- cular to trigonous achene CYPERACEAE 45 11 Plants with usually terete stems and mostly not 3- ranked leaves, rarely at all grasslike; perianth seg- ments usually in two series of (2) 3 each; fruit various 12 Pistils more than one, quite distinct, or the carpels more or less connate, but separating at maturity into 3 or 6 follicles 13 Perianth inconspicuous, greenish, the segments all essentially alike; carpels 3-6 JUNCAGINACEAE 40 13 Perianth rather showy, the sepals green, the petals white to pink or purplish; carpels 6 or more ALISMATACEAE SAGITTARIA CUNEATA Sheld. 12 Pistil one, compound, 1- or 3-celled, the fruit not follicular 14 Plants grasslike; flowers inconspicuous, the perianth mostly greenish to. brownish or pur- lish-green, the segments all essentially like JUNCACEAE 42 14 Plants scarcely or not at all grasslike; perianth usually more or less showy, the corolla often not at all like the calyx in color 15 Ovary superior LILIACEAE 82 15 Ovary inferior 16 Plants aquatic, usually submersed, mostly dioecious; stamens (1) 3-12 HYDROCHARITACEAE ELODEA CANADENSIS Rich. 16 Plants terrestrial, perfect-flowered; stamens 1-3 17 Stamens 3, free of the style; flowers regular IRIDACEAE 85 17 Stamens 1 or 3, joined with the style; flowers very irregular ORCHIDACEAE 86 5 MAGNOLIATAE or Dicotyledons 1 Plants branch-parasites at maturity, without roots, not arising from underground LORANTHACEAE 96 1 Plants not branch-parasites, either rooted (and usually arising from underground) or free-floating (i.e. aquatic) 2 Plants non green saprophytic or parasitic herbs with leafless or merely bracteate stems 3 Corolla bilabiate, gamopetalous; stamens 4; placentae 2-3; plants root-parasite OROBANCHACEAE 187 3 Corolla not bilabiate, often polypetalous; stamens 6-10; placentae 4-8; plants saprophytes (several genera) ERICACEAE 165 2 Plants chlorophyllous (but sometimes partially para- sitic) , usually with greenish leaves 4 Flowers modified into bulblets and without normal floral parts; herbaceous plants 5 Stipules sheathing the stem; leaves entire (Polygonum) POLYGONACEAE 97 5 Stipules not sheathing the stem; leaves toothed (Lithophragama, Saxifraga) SAXIFRAGACEAE 132 4 Flowers (mostly or all) normal, not modified into bulblets; herbaceaous to arborescent plants 6 Plants aquatic, typically with the stems submerged or floating and too flaccid to project out of the water although flowering stems, only, sometimes pro- duced above the water (not including those plants that start their growth under water, but eventually flower on the wet or dried mud of vernal pools and mud banks, where they may produce erect or ascending stems) GROUP I 11 6 Plants terrestrial or semi-aquatic but eventually emergent and with erect flowering stems 7 Leaves adapted to the trapping of insects, by flat blades covered with long, purplish, gland-tipped hairs; plants of wet places; petals separate DROSERACEAE DROSERA ANGLICA Huds. 7 Leaves not adapted to the trapping of insects as above; plants of various habitats; corolla often either petals united or lacking 6 8 Plants apparently leafless, the stems greatly enlarged and flattened and jointed or globose to cylindric, often ribbed or fluted, armed with stiff spines CACTACEAE 157 8 Plants usually leafy, if stems succulent and enlarged then not spiny 9 Stem woody or at least persistent and perennial above ground; plants mostly trees, shrubs, or woody vines; here are included many matforming species and sev- eral plants with herbaceous and greenish but persist- ent stems, such as the English Ivy, but not included are most plants with more or less erect herbaceous stems arising from only a small woody persistent base 10 Plants viny or creeping, erect only when supported GROUP II 12 10 Plants neither viny nor creeping, although some- times matted, usually erect 11 Leaves and stems silvery to reddish with a close covering of tiny, minutely fringed scales the scales barely visible with a 10-power lens (best seen on the older parts of the stem); entire-leaved shrubs; flowers apetalous, peri- gynous, with 4 or 8 stamens borne on a 4-lobed calyx ELAEAGNACEAE 157 11 Leaves and stems not silvery with fringed scales, but otherwise pubescent to glabrous; flowers diverse 12 Plants armed with spines, thorns, or prickles along or at the tips of the branches (including those plants with the branches ending in true tapered spines, but not those with rigid, some- what pointed, untapered branch ends) GROUP III 13 12 Plants without spines, thorns, or prickles on the stems, but very occasionally spiny or prickly on the margins or segments of the leaves, the branch tips sometimes pungent but not really spinose 13 Leaves scalelike, overlapping only 1-5 mm long 14 Flowers several in an involucrate head; stamens 5, usually connate around the style, ovary inferior (Stephanomeria) COMPOSITAE 193 7 14 Flowers not in involucrate heads; stamens often other than 5, not connate; ovary usually superior POLEMONIACEAE 171 13 Leaves not truly scalelike and overlapping, although often longer than the internodes 15 Leaves mainly opposite (not including those plants with internodes so short the leaves are bunched) GROUP IV 14 15 Leaves mainly alternate but occasionally some approximate or even totally opposite (including those plants with leaves so close together that their true arrangement is not apparent) 16 Corolla gamopetalous; stigmas 3; stems herba- ceous or only semi-woody at base; leaves mostly lobed to compound, the segments often pointed or sharp POLEMONIACEAE 171 16 Corolla polypetalous (lacking) or if gamopetalous then the stigmas not 3; stems often truly woody; leaves various 17 Leaf blades apically trilobed to dissected or compound GROUP V 15 17 Leaf blades simple, with an entire to lobed margin GROUP VI 17 Stems herbaceous (including all annuals and those peren- nials that usually die back to the crown or to no more than a small persistent woody base) 18 Flowers in capitate clusters surrounded by usually numerous, often spine-tipped bracts, the spines (if any) either straight and sharp or sometimes hooked, the whole inflorescence (head) sometimes forming a dis- tinct bur; petals united; stamens 5, usually united around the style; ovary inferior, 1-celled, and 1-seeded COMPOSITAE 193 18 Flowers rarely in involucrate heads, if so either the corolla (if any) polypetalous, the stamens distinct, or the ovary not at once inferior, 1-celled, and 1-seeded 19 Milky juice present; leaves mostly simple and opposite but sometimes alternate or more or less dissected and then either the flowers naked and borne in a cupulate often perianth like involucre (the pistil 3-carpellary and 3-celled) , or the seeds hairy GROUP VII 18 19 Milky juice lacking; leaves and flowers diverse 8 20 Leaves in considerable part whorled, 3 or more per node (not including those with the leaves all basal) GROUP VIII 20 Leaves not whorled but alternate, opposite, or all basal; sometimes the main leaves with axillary fascicles of secondary leaves 21 Flowers polypetalous and very strongly irregular, generally showy, the petals usually distinct but not rarely at least 1 pair connate at base, the irregularity because of one of the following conditions; 1 of the petals much the largest, 1 or 2 of the petals strongly spurred or saccate, calyx spurred to saccate or hooded, or flower with a large lopsided disc; sepals sometimes only 2 and greatly reduced in size GROUP IX 21 21 Flowers not strongly irregular if petals separate, often without petals or the petals all jointed into a common tube at base (gamopetalous) ; sepals usually more than 2 or (if 2) not greatly reduced in size 22 Leaves opposite, glabrous, entire, sessile, often covered with tiny translucent or blackish dots; stamens numerous , hypogynous, sometimes weakly connate into 3-5 groups; ovary superior, either 3- celled or 1-celled HYPERICACEAE 154 22 Leaves, stamens, and ovary not at once as above 23 Leaves brittle, very rough and gritty, alter- nate, exstipulate, pubescent with finely bar- bellate hairs (barbs barely visible with a 10- power lens); stamens numerous; ovary infer- ior, 1-celled, the placentation parietal LOASACEAE 156 23 Leaves not brittle and barbellate-pubescent, sometimes opposite or stipulate; either the ovary not inferior and 1-celled or the stamens numerous 24 Perianth 4-merous, the corolla polypetalous or absent; stamens mostly 4 or 8 (rarely 2) not infrequently 6, when (as rarely) more than 8 the ovary always superior, 1-celled, and with 3 parietal placentae GROUP X 22 24 Perianth usually not 4-merous, the corolla gamopetalous, or plant otherwise not as above 9 25 Pistil one, 5 (2 to 8) -carpellary, the carpels 1-seeded, weakly connate around an elongate, tapered receptacle extending above the calyx, the fruits separating at maturity; petals 5, distinct; stamens 10 (sometimes only 5 fertile) GERANIACEAE 153 25 Pistils sometimes more than 1, if single then not com- posed of 5 carpels that separate at maturity, receptacle not greatly elongate; petals and stamens various 26 Leaf blades pinnately, ternately, or palmately divided to compound 27 Flowers clustered in heads surrounded by few to many bracts; ovary inferior; corolla gamopet- alous; calyx often lacking or greatly modified COMPOSITAE 193 27 Flowers rarely involucrate heads but if so either the corolla polypetalous or the ovary superior 28 Corolla polypetalous or lacking GROUP XI 23 28 Corolla gamopetalous GROUP XII 24 26 Leaf blades mostly entire or toothed to lobed, neither deeply palmatifid or pinnatifid nor compound 29 Perianth parts alike, not consisiting of 2 dis- similar series (usually the corolla the series that is vestigial or lacking) , sometimes represented by 2 or more series of essentially similar bract like members 30 Stamens hypogynous, not borne on the perianth GROUP XIII 25 30 Stamens perigynous or epigynous, borne on the perianth which may be adnate to the ovary GROUP XIV 27 29 Perianth evidently consisiting of both the calyx and corolla 31 Corolla polypetalous GROUP XV 29 31 Corolla gamopetalous GROUP XVI 31 10 GROUP I Leaves generally floating; stipules membranous, usually connate around the stem; pistil 1, usually with 3 stigmas only 1 seed (Polygonum) POLYGONACEAE 97 Leaves often submerged; stipules not connate and sheath- ing; pistil either more than 1 or with other than 3 stigmas but only 1 seed 2 Plants rooted in the mud; leaves with greatly elongate, flaccid petioles and peltate to cordate, subentire, floating blades NYMPHAEACEAE NUPHAR POLYSEPALUM Engelm 2 Plants either floating or with leaves other than as above 3 Leaves trifoliolate or simple and cordate-ovate (the leaflets or blades 3-12 cm long), alternate, long- petiolate, with sheathing bases MENYANTHACEAE MENYANTHES TRIFOLIATA L . 3 Leaves neither trifoliolate nor cordate-ovate, often opposite or whorled, the blades or leaf segments mostly less than 3 cm long, the bases rarely sheath- ing 4 Submerged leaves dissected and bearing small, ovoid, insect-trapping bladders (Utricularia) LENTIBULARIACEAE 188 4 Submerged leaves not bladder-bearing 5 Leaves whorled; stems submerged or if emer- gent the leaves linear and entire 6 Leaves entire, mostly linear 7 Whorls usually of at least 5 leaves HIPPURIDACEAE HIPPURIS VULGARIS L. 7 Whorls usually of only 3-4 leaves CALLITRICHACEAE CALLITRICHE ANCEPS Fern. 6 Leaves dissected 8 Leaf blades once or twice palmately or dichotomously dissected, the ultimate segments usually 2-4 CERATOPHYLLACEAE CERATOPHYLLUM DEMERSUM L 8 Leaf blades pectinately dissected to sub- entire, the ultimate segments usually 7-15 HALORAGIDACEAE MYRIOPHYLLUM SPICATUM L . ■ 1 1 5 Leaves alternate, opposite, or all basal; stems often emergent but with other than linear leaves 10 Flowers naked, tiny, axillary; leaves opposite , those submerged linear and 1-nerved, those floating or emergent broadened and 3- to 5-nerved CALLITRICHACEAE CALLITRICHE ANCEPS Fern. 10 Flowers with a perianth; leaves not as above in all respects 11 Pistils several; leaves often dissected (Ranunculus) RANUNCULACEAE 111 11 Pistil 1; leaves rarely dissected 12 Sepals 2; petals 4-5, distinct (Montia) PORTULACACEAE 105 12 Sepals other than 2, sometimes lacking; petals various 13 Sepals and petals 4, distinct; ovary superior 14 Stamens 8; ovary 4-celled ELATINACEAE ELATINE TRIANDRA Schkuhr. 14 Stamens 2, 4, or 6; ovary (1) 2-celled CRUCIFERAE 119 13 Sepals and petals mostly other than 4, if 4 then connate or the ovary inferior 15 Stems usually square; ovary 4-lobed; fruit 4-nutlets LABIATAE 178 15 Stems not square; ovary not 4-lobed; fruit a (1) 2-celled capsule (Veronica) SCROPHULARIACEAE 180 GROUP II 1 Leaves alternate, exstipulate, persistent, pinnately com- pound, the leaflets leathery, spiny-toothed; stems unarmed BERBERIDACEAE MAHONIA REPENS (Lindl . )G .Don 1 Leaves otherwise , often opposite , deciduous, stipulate, or neither pinnate nor spiny-toothed 2 Leaves in greater part opposite or whorled 3 Leaf blades ternately to pinnately compound (Clematis) RANUNCULACEAE 111 3 Leaf blades simple 4 Venation of the leaves prominent, the lateral veins more or less parrallel with the midrib; stems erect, 12 herbaceous, with a whorl of leaves near the tip; flowers in heads subtended by white or pink bracts CORNACEAE 165 4 Venation usually not at all parallel; leaves not whorled; flowers not white- or pink-bracteate 5 Ovary inferior; leaves sometimes connate-perfoliate (Linnaea, Lonicera) CAPRIFOLIACEAE 190 5 Ovary superior; leaves not connate-perfoliate 6 Plants mostly strongly aromatic; ovary 4-lobed and 4-seeded (Glecoma, Lamium, Nepeta) LABIATAE 178 6 Plants not aromatic; ovary not 4-lobed, usually many-seeded SCROPHULARIACEAE 180 2 Leaves alternate 7 Stamens 8 or 10; anthers opening by terminal pores; corolla gamopetalous; fruit a 4- or 5-celled capsule or berry, often persistent through the winter (Arctostaphylos , Gaultheria, Vaccinium) ERICACEAE 165 7 Stamens often other than 8 or 10, not opening by ter- minal pores; corolla polypetalous or lacking; fruit rarely 4- or 5-celled if capsular or baccate 8 Leaves 3- to 5-foliolate, deciduous, exstipulate, the leaflets smooth and shining; plants erect or clambering ANACARDIACEAE 154 8 Leaves often simple, persistent, or stipulate; stems often trailing; leaflets mostly not shining (Dryas, Potentilla, Rubus) ROSACEAE 137 GROUP III 1 Stems with prickles or spines other than at the branch ends; leaves palmately lobed; pistil 1; ovary inferior, 5- to many-seeded GROSSULARIACEAE 136 1 Stems various, but if prickly either the leaves not palmately lobed, the pistils more than 1, or the ovary either superior or with fewer than 5 seeds 2 Branches and leaves more or less grayish-villous or -tomentose; leaves exstipulate, linear, or pedately 3- to 5-parted (Tetradymia) COMPOSITAE 193 2 Branches and leaves seldom if ever grayish-tomentose but if so the leaves neither linear nor pedately parted 13 3 Corolla present; stamens usually more than 5; pistils numerous (Rubus) ROSACEAE 137 3 Corolla lacking; stamens 5 or fewer; ovary 1-celled and 1-seeded; fruit dry (Atriplex, Grayia, Sarcobatus) CHENOPODIACEAE 101 GROUP IV 1 Plants woody only at the basal portion of the stems, the growth of each season largely nonpersistent 2 Juice milky; seeds usually hairy APOCYNACEAE 170 2 Juice not milky; seeds rarely hairy 3 Corolla gamopetalous; ovary inferior CAPRIFOLIACEAE 190 3 Corolla sometimes polypetalous (lacking), if gamopetalous the ovary superior 4 Flowers 4-merous; ovary inferior , usually 4-celled CORNACEAE 165 4 Flowers mostly not 4-merous; ovary superior 5 Corolla regular, strongly gamopetalous; stigmas 3; ovary 3-celled or 3- to many-seeded POLEMONIACEAE 171 5 Corolla irregular if strongly gamopetalous, sometimes lacking; ovary often only 1-seeded if 3-carpellary 6 Leaves usually succulent or with a mealy covering; corolla lacking; ovary 1-seeded CHENOPODIACEAE 1 0 1 6 Leaves neither succulent nor with a mealy covering; corolla present; ovary more than 1-seeded SCROPHULARIACEAE 180 1 Plants woody throughout, the growth of each season largely persistent 7 Leaves palmately lobed to pinnately compound ACERACEAE ACER GLABRUM Torr . 7 Leaves simple, usually entire to merely toothed 8 Stems and leaves often more or less pubescent with appressed, 2-armed hairs; leaves prominently veined, the main lateral veins tending to parallel the midnerve; stems often reddish; flowers sometimes in white-bracteate heads CORNACEAE 165 14 8 Stems not pubescent with 2-armed hairs; stems mostly not red; flowers never in white-bracteate heads 9 Stamens 10, hypogynous, the anthers often opening by terminal pores; flowers complete; ovary 5-celled (Chimaphila, Kalmia) ERICACEAE 165 9 Stamens other than 10 if hypogynous, or flowers incomplete or ovary not 5-celled 10 Calyx 4-lobed; stamens 8, borne on the calyx; corolla absent; leaves silvery- or rusty-scurfy beneath (Shepherdia) ELAEAGNACEAE 157 10 Calyx not 4-lobed; if stamens 8; corolla often present; leaves rarely silvery or rusty beneath 11 Plants, at least the leaves, usually mealy- covered, often also somewhat glandular CHENOPODIACEAE 101 11 Plants, even the leaves, never mealy, rarely glandular 12 Leaves coriaceous, persistent, oblong to obovate, 1-2.5 cm long, with persistent, thickened stipules 1-2 mm long; stamens 5, opposite the 5 hooded petals; flowers perigy- nous (Ceanothus) RHAMNACEAE 154 12 Leaves diverse, mostly inconspicuously sti- pulate (or exstipulate); either the stamens alternate with the petals (if any) or flowers epigynous CAPRIFOLIACEAE 190 GROUP V 1 Leaves apically trilobed to ternately or palmately divided, dissected, or compound (never pinnately compound) 2 Plants stellate-pubescent; stems woody (Physocarpus) ROSACEAE 137 2 Plants not stellate-pubescent 3 Leaf blades obovate-oblanceolate, 3-toothed at the apex, green above, white-woolly beneath, deciduous from the broadened, membranous base with which the small toothlike stipules remain; branches stiff and rigid (Purshia) ROSACEAE 137 15 3 Leaf blades mostly not 3-toothed apically, but when so either persistent or without a persistent stippular base 4 Leaf blades palmately lobed; corolla polypetalous 5 Stipules prominent, not fused lengthwise with the petiole; stamens and pistils numerous (Rubus) ROSACEAE 5 Stipules lacking or fused their length with the petiole; stamens 5; pistil 1 GROSSULARIACEAE 136 4 Leaf blades not palmately lobed or corolla not polypeta- lous 6 Flowers not in involucrate heads; leaves ternate, the segments shallowly to deeply lobed 7 Stamens 25 or more; pistils several (Rubus) ROSACEAE 137 7 Stamens less than 15; pistil 1 ANACARDIACEAE 154 6 Flowers in involucrate heads; leaves rarely ternate COMPOSITAE 193 1 Leaves pinnately compound 8 Leaflets glossy and shining, pungent-toothed; leaves persistent BERBERIDACEAE MAHONIA REPENS (Lindl.) G.D. 8 Leaflets usually not glossy, not pungent-toothed; leaves often deciduous 9 Leaves stipulate (the stipules sometimes deciduous); stamens 15-100 (Potentilla, Rubus, Sorbus) ROSACEAE 137 9 Leaves exstipulate; stamens less than 15 10 Leaves rarely less than 4 cm long; leaflets elliptic to ovate or obovate, toothed, never tomentose ANACARDIACEAE 154 10 Leaves often less than 4 cm long; leaflets mostly linear, often woolly (Artemisia, Tanacetum) COMPOSITAE 193 16 GROUP VI Plants low, woody-branched, heathlike shrubs having closely crowded, linear, entire, evergreen, often revolute-margined leaves , montane ERICACEAE 165 Plants not heathlike, often in large part herbaceous (sometimes cushion-forming), if with linear, revolute- margined leaves then usually of desert or saline areas 2 Plants mostly semishrubby, the annual branches tending to die back toward the woody base 3 Leaves exstipulate, often narrow, usually strongly excrescent-mealy, but sometimes grayish- or yellow-hairy (sometimes stellate) or glabrous and very succulent; flowers apetalous, inconspicuous, never umbellate, often imperfect; styles 2 (rarely 3 or 4); ovary 1-celled and l~seeded CHENOPODIACEAE 101 3 Leaves and flowers not at once as above 4 Flowers capitate or umbellate, usually involucrate; leaves often linear or woolly (at least beneath) COMPOSITAE 193 4 Flowers not involucrate, rarely borne in umbels or heads; leaves diverse 5 Leaves mostly stipulate; stamens usually more than 10; flowers perigynous (epigynous), poly- petalous or apetalous; pistil sometimes more than 1, never 2-celled or 1-celled with 2 or 3 parietal placentae ROSACEAE 137 5 Leaves often exstipulate; stamens rarely more than 10; flowers often hypogynous, sometimes gamopetalous; pistil 1, sometimes 2-celled or 1-celled with 2 or 3 parietal placentae 6 Fertile stamens 4 (a fifth one sterile); corolla more or less bilabiate (Penstemon) SCROPHULARIACEAE 1 8 0 6 Fertile stamens usually 5 or more; corolla mostly regular ERICACEAE 165 2 Plants true shrubs or trees (sometimes cushion- forming) 7 Corolla gamopetalous; stamens 5, 8 or 10 ERICACEAE 165 7 Corolla polypetalous or wanting; stamens diverse 17 8 Flowers apetalous , imperfect, the staminate (sometimes also the pistillate) borne in crowded bracteate racemes or spikes (aments or catkins) 9 Leaves usually mealy-scurfy at least beneath; styles 2; ovary 1-seeded, superior (Atriplex) CHENOPODIACEAE 1 0 1 9 Leaves rarely at all mealy-scurfy; styles often other than 2; ovary sometimes inferior or many-seeded SALICACEAE 89 8 Flowers often petaliferous , perfect or imperfect, but neither the staminate nor the pistallate in catkins 10 Stamens usually more than 10, if 10 or fewer then the plant cushion-forming or the pistil more than 1 ROSACEAE 137 10 Stamens 4-10; plant never cushion-forming; pistil 1 11 Ovary 1-celled and 1-seeded; petals lacking; stamens opposite the sepals ELAEAGNACEAE 157 11 Ovary 2- to 3-celled or several-seeded; petals often present; stamens sometimes opposite the petals (if any) and thus alternate with the sepals 12 Stamens opposite the petals; leaves never pal- mately lobed; ovary superior RHAMNACEAE 154 12 Stamens alternate with the petals; leaves some- times palmately lobed; ovary inferior GROSSULARIACEAE 136 GROUP VII 1 Flowers apetalous; ovary 3-carpellary and 3-celled, each cell 1-seeded; seeds not hairy EUPHORBIACEAE 153 1 Flowers with a usually more or less showy corolla; ovary 2-carpellary; seeds often hairy 2 Ovary inferior, 1-celled and 1-seeded (Tribe Cichorieae) COMPOSITAE 193 2 Ovary superior, 1- or 2-celled, multiseeded 3 Corolla lobed well over half its length or the lobes not reflexed; stamens completely fused surrounding and adnate with the style and stigma ASCLEPIADACEAE ASCLEPIAS SPECIOSA Torr . 18 3 Corolla ordinarily lobed less than half the length or the lobes not reflexed; stamens free or only partially connate, weakly if at all adnate to the style and stigma APOCYNACEAE 170 GROUP VIII 1 Corolla gamopetalous , rotate, the segments with large fringed glands near the base; stamens as many as the petals and alternate with them (Frasera) GENTIANACEAE 169 1 Corolla (if any) often polypetalous , if gamopetalous then not rotate or the segments not gland-bearing near the base; stamens often more numerous than the petals 2 Corolla gamopetalous 3 Flowers in involucrate heads, the 5 stamens usually connate around the style; ovary inferior, 1-celled and 1-seeded (Eupatorium) COMPOSITAE 193 3 Flowers not in involucrate heads; stamens and ovary various 4 Ovary inferior, 2-seeded; stems often square RUBIACEAE 189 4 Ovary superior , several-seeded; stems mostly not square 5 Ovary usually 4-lobed and 4-ovuled, developing into 4 (or by abortion only 1, 2, or 3) 1-seeded nutlets; plants often harsh- pubescent 6 Stamens 4 or 5; corolla only slightly irregular; style terminal on the ovary or nutlets VERBENACEAE VERBENA BRACTEATA Lag . 6 Stamens 2 or 4; corolla usually strongly irregular; style attached toward the base of the nutlets or ovary lobes LABIATAE 178 5 Ovary not 4-lobed, or at least not developing into 4 nutlets; plants not harsh-pubescent 7 Stigmas usually 3 (2); stamens alternate with the corolla lobes; placentation not free-central POLEMONIACEAE 171 19 7 Stigma usually capitate and single; stamens opposite the corolla lobes; placentation free-central PRIMULACEAE 168 Corolla, if any, polypetalous (rarely some or all of the segments weakly connate at base) 8 Stamens usually more than 10; pistils more than I, simple RANUNCULACEAE 111 8 Stamens mostly 10 or fewer; pistil single, usually compound 9 Leaves entire, more or less parallel-veined, lightly pubescent with 2-armed, sessile (malpighiaceous) hairs; flowers clustered and surrounded by 4 large white or pinkish bracts CORNACEAE 165 9 Leaves not both parallel-veined and malpighiaceous- pubescent; flowers not subtended by large white bracts 10 Stamens hypogynous, as many as the corolla lobes and opposite them; ovary 1-celled; placentation free-central; style and stigma 1 PRIMULACEAE 168 10 Stamens sometimes perigynous or epigynous, usually as many as the corolla lobes and alter- nate with them, or twice as many; ovary and styles diverse 11 Leaves usually not whorled the full length of the stems (often only at 1 node); perianth usually in part other than greenish; pistil 1, compound; ovary 1-celled and 1-seeded or styles or stigmas 3 (2-4) or the sepals either 2 or 5-9 12 Seeds numerous; perianth in 2 series, the petals 5-20, usually showy; calyx of either 2 or 5-9 sepals PORTULACACEAE 105 12 Seeds one; perianth scarcely differentiated into 2 unlike series, rarely showy, usually 3-6 (often greenish) segments POLYGONACEAE 97 11 Leaves whorled at most of the nodes or the perianth (if any) greenish; ovary and sepals various 20 13 Leaves linear, sessile; stamens 1, the flowers usually imperfect HIPPURIDACEAE HIPPURIS VULGARIS L . 13 Leaves often petiolate if linear then the stamens 3 or more C ARYOPH YLLACEAE 1 0 7 GROUP IX 1 Petals 3, the lower crested; sepals 5, the inner two petaloid; ovary 2-celled, latterally compressed, 1 seed per cell POLYGALACEAE POLYGALA ALBA Nutt . 1 Petals 5; sepals and ovaries otherwise 2 Stamens 6, connate into 2 groups of 3 each; sepals 2, tiny, often quickly deciduous; petals 4, one or both of the outer pair usually spurred or saccate FUMARIACEAE 119 2 Stamens usually 5, 10, or more, not connate into 2 equal groups; sepals 3 or more; petals 3 or 5, often not spurred 3 Calyx usually petaloid and more showy than the corolla, 1 sepal strongly saccate, hooded, or spurred RANUNCULACEAE 111 3 Calyx mostly not petaloid, rarely more showy than the corolla, usually greenish, rarely spurred and if so the spur not formed by a single sepal 4 Lowest petal of the corolla the largest; stamens 5, connate around the pistil; ovary with 3 parietal placentae VIOLACEAE 155 4 Lowest petal of the corolla usually not the largest (the lowest pair of petals often partially united and then sometimes the two larger than the upper petal); stamens and ovary various 5 Upper petal of the flower much the largest; stamens often connate; ovary 1-celled with 1 parietal placenta LEGUMINOSAE 143 5 Upper petal usually not the largest; stamens not connate; ovary 2- to 5-celled or with 2 parietal placenta 6 Stamens hypogynous, the anthers dehiscent by terminal pores; ovary (4) 5-celled (Pyrola) ERICACEAE 165 21 6 Stamens perigynous or epigynous, the anthers not dehis- cent by terminal pores; ovary usually 1- or 2 (3) -celled (Saxifraga) SAXIFRAGACEAE 132 GROUP X 1 Ovary partially to wholly inferior; stamens 4 or 8 2 Flowers clustered, subtended by several large white or pinkish bracts; fruit fleshy CORNACEAE 165 2 Flowers not subtended by large white bracts; fruit a capsule ONAGRACEAE 157 1 Ovary superior 3 Stipules sheathing the stem above the petiole; stigmas strongly fringed (Oxyria) POLYGONACEAE 97 3 Stipules not sheathing the stem; stigmas entire or lobed 4 Leaves oppsite, stipulate; stamens 8; ovary 4-celled; diminutive, usually prostrate annuals ELATINACEAE ELATINE TRIANDRA Schkuhr. 4 Leaves rarely if ever both opposite and stipulate; stamens seldom 8; ovary 1- or 2-celled 5 Stamens 4; corolla absent or vestigial; calyx unequally (3) 4-lobed; ovary 2-celled, the pla- centation axile (Besseya) SCROPHULARIACEAE 180 5 Stamens often other than 4; corolla usually present, polypetalous; calyx usually equally lobed; ovary 1-celled or if 2-celled then with parietal placentation 6 Ovary 1-celled, nearly always borne on a stalk projecting above the point of insertion of the stamens, when sessile the stamens more than 6; fruit many-seeded CAPPARIDACEAE CLEOME SERRULATA Pursh. 6 Ovary usually 2-celled, but when (as rarely) 1- celled then not stalked and usually only 1- or 2- seeded; stamens never more than 6 CRUCIFERAE 119 22 GROUP XI Stamens more than 10, monadelphous , forming a tube surrounding the pistil; plants often strongly stellate- pubescent MALVACEAE 154 Stamens not monadelphous if more than 10; plants usually not stellate-pubescent 2 Petals, sepals, and stamens usually 5; pistil 1, the ovary inferior, 2- to 6-celled, with 1 seed per cell; flowers mostly in flat- to round-topped umbels or heads UMBELLIFERAE 160 2 Petals, sepals, or stamens sometimes not 5; pistils sometimes more than 1, if only 1 then ovary superior or with more than 1 seed per cell; flowers rarely umbellate 3 Flowers with more than 1 pistil or with more than 15 stamens; pistils always simple, with only 1 placenta and often with only 1 seed 4 Stamens hypogynous, borne on the receptacle, a disc lacking; sepals often deciduous, frequently petaloid, not leathery; leaves exstipulate RANUNCULACEAE 111 4 Stamens perigynous to epigynous, borne on the calyx or on (or at the edge of) a disc surrounding the pistils; sepals sometimes leathery and per- sistent; leaves often stipulate 5 Leaves exstipulate, ternately decompound; stamens borne on and at the edge of a prom- inent lobed disc that is free of the calyx; fruits large, leathery, many-seeded follicles; sepals leathery, persistent PAEONIACEAE PAEONIA BROWNII Dougl . 5 Leaves usually strongly stipulate (at least when ternately compound) stamens usually borne on the calyx or on a disc adnate to the calyx; fruits and sepals diverse ROSACEAE 137 3 Flowers with only 1 pistil, usually with less than 15 stamens (if with more than 10 stamens the pistil always compound) 23 6 Pistil 1; ovary usually 1-celled and with 1 parietal placenta, but very rarely with a false partition, and the placentae adjacent on one side of the 2 cavities; stamens either 5 and distinct or 10 and monadelphous or diadelphous; leaves mostly strongly stipulate (Astragalus) LEGUMINOSAE 143 6 Pistil rarely only 1 and ovary 1-celled and with 1 parietal placenta, but if so the stamens neither 5 and distinct or 10 and connate (if ovary 2-celled, the placentae not immediately adjacent on one side); leaves sometimes exstipulate 7 Flowers perigynous or epigynous; sepals slightly to strongly connate, often alternately bracteate 8 Stamens mostly 3, 5, or 10; pistil 2 to 3 (very rarely 4) -carpellary; calyx not bracteate and never with a ring of stiff hooked bristles SAXIFRAGACEAE 132 8 Stamens often more than 10; pistil 1-carpellary (with only 1 seed or placenta); calyx often with bracts alternate with the lobes ROSACEAE 137 7 Flowers hypogynous; sepals (if any) almost or quite distinct, without alternating bracts LIMNATHACEAE FLOERKEA PROSERPINACOIDES Willd. GROUP XII 1 Corolla prominently scaly-hairy; leaves trifoliolate; ovary 1-celled MENYANTHACEAE MENYANTHES TRIFOLIATA L . 1 Corolla not scaly-hairy, or leaves not trifoliolate, or ovary more than 1-celled 2 Ovary partially to completely inferior 3 Leaves pinnate; corolla irregular; stamens 1-4 VALERIANACEAE 192 3 Leaves ternate; corolla regular; stamens 8-10 ADOXACEAE ADOXA MOSCHATELLINA L . 24 2 Ovary superior 4 Stigmas 3 POLEMONIACEAE 171 4 Stigmas 1 or 2 5 Corolla regular; fertile stamens 5; fruit a capsule or berry 6 Flowers borne in 1-sided helicoid inflorescences HYDROPH YLLACEAE 1 7 4 6 Flowers not borne in helicoid inflorescences 7 Ovary 1-celled; fruit a nonspiny, valvate capsule HYDROPHYLLACEAE 174 7 Ovary 2- to 5-celled; fruit a berry or a some- times spiny or circumscissile capsule SOLANACEAE 180 5 Corolla irregular; fertile stamens often other than 5; fruit sometimes 1-4 nutlets 8 Ovary deeply 4-lobed, forming four 1-seeded nutlets; stems usually square; plants (other than the flowers) often strongly aromatic 9 Style terminal on the ovary or nutlets; corolla only slightly irregular; stamens 4 or 5; flowers in terminal, bracteate spikes VERBENACEAE VERBENA BRACTEATA Lag . 9 Style sub-basal on the ovary segments; corolla strongly irregular; stamens 2-4; inflorescence diverse LABIATAE 178 8 Ovary unlobed or bilobed; fruit a many-seeded capsule; stems rarely square; plant rarely aromatic 10 Stamens usually 4 or 5, distinct; ovary 2-celled; sepals 4 or 5 SCROPHULARIACEAE 180 10 Stamens often 6 and joined into 2 groups; ovary 1-celled; sepals 2 FUMARIACEAE 119 GROUP XIII 1 Pistils more than 2, simple; stamens often more than 10 RANUNCULACEAE 111 1 Pistil 1, often compound, but sometimes only the lower part of the carpels fused; stamens usually no more than 10 25 2 Perianth (the calyx) 2-lipped; stamens 2; ovary 2-celled, many-seeded; flowers perfect (Besseya) SCROPHULARIACEAE 2 Perianth not 2-lipped; stamens rarely 2; ovary mostly either 1-seeded, or with only 1 seed per cell, or 1-celled with free-central placentation 3 Perianth parts only 2; stigmas 3; ovary 1-celled, 2- to many-seeded (Montia) PORTULACACEAE 3 Perianth parts usually either more than 2 or completely lacking; stigmas rarely 3 if the ovary is 1-celled and several -seeded 4 Ovary multiseeded; placentation free-central (at least in the upper part of the ovary); leaves opposite at least on the lower part of the stem, the nodes often swollen 5 Style and stigma 1; stamens as many as, and alter- nate with, the sepals (Glaux) PRIMULACEAE 5 Styles or stigmas (2) 3-5; stamens often twice as many as the sepals (Arenaria, Cerastium, Stellaria) CARYOPHYLLACEAE 4 Ovary 1- to 3-seeded; placentation mostly basal; leaves diverse 6 Stipules more or less connate and sheathing the stem above the node POLYGONACEAE 6 Stipules, if any, not sheathing 7 Leaves opposite , exstipulate; perianth connate, campanulate to funnel-form or tubular; style and stigma 1; ovary 1-seeded, closely surrounded by the base of the calyx, which is usually thickened NYCTAGINACEAE ABRONIA FRAGRANS Nutt . 7 Leaves often alternate or stipulate; perianth usually not strongly connate; styles, stigmas, or seeds often more than 1 8 Ovary 3-lobed, 3-celled, 3-seeded; flowers really naked and imperfect but apparently con- sisting of several stamens (each stamen a separate flower), 1 pistil (also a separate flower) , and a uniseriate perianth (in reality an involucre) EUPHORBIACEAE 8 Ovary 1 (2) -celled; flowers mostly with a perianth but without an involucre 26 9 Perianth usually showy, generally in 2 similar or dis- similar series; stamen 3-9; stigma or styles 3 POLYGONACEAE 97 9 Perianth not at all showy, rarely colored 10 Plant with opposite, stipulate leaves and stinging hairs (Urtica) URTICACEAE 96 10 Plant often alternate-leaved, mostly without stipules, never with stinging hairs 11 Plants stellaterpubescent (at least in the inflores- cence) but sometimes tardily glabrate (Eurotia) CHENOPODIACEAE 101 11 Plants not stellate-pubescent 12 Leaves linear, nearly terete, rigidly pungent- tipped, sometimes pilose at base; ovary wall more or less adherent to the seed (Salsola) CHENOPODIACEAE 101 12 Leaves usually expanded, not pilose-based, rarely pungent; fruit a capsule, the wall free of the seed 13 Perianth dry and more or less membranous, the segments often sharp-pointed; flowers subtended by scarious, pungent bracts; leaves rarely either succulent, scurfy, or copiously soft-hairy AMARANTHACEAE 105 13 Perianth mostly not dry and membranous, the segments rarely pungent and the flowers not usually pungent-bracteate; leaves usually either succulent, strongly scurfy, or densely soft-pubescent CHENOPODIACEAE 1 0 1 GROUP XIV 1 Flowers borne in heads surrounded by a 1- to several- seriate involucre; ovary inferior, 1-celled and 1-seeded; style branches 2; stamens usually (but not always) connate around the style COMPOSITAE 193 1 Flowers rarely involucrate heads, if capitate the ovary superior or more than 1-seeded, or the style branches other than 2; stamens not connate around the style 2 Perianth irregular, usually spurred at the base; stamens fewer than the perianth lobes; leaves opposite; stigma 2- or 3-lobed VALERIANACEAE 192 27 Perianth regular, not spurred; stamens mostly at least as many as the perianth lobes; leaves often alternate; stigmas often simple 3 Styles or stigmas 2 or 3; ovary 1-celled and 1-seeded 4 Perianth dry and scarious, the flowers surrounded by sharp-pointed bracts; fruit a circumscissile capsule AMARANTHACEAE 105 4 Perianth not dry and scarious; flowers not pungent- bracteate; fruit not cicumscissile POLYGONACEAE 97 3 Styles or stigmas other than 2 or 3 or the ovary not 1-celled and 1-seeded 5 Leaves opposite (but not all basal), exstipulate NYCTAGINACEAE ABRONIA FRANGRANS Nutt. 5 Leaves either alternate (or all basal) or stipulate 6 Flowers umbellate to subcapitate, with or without an involucre; styles 2; ovary 2-celled, each cell 1-seeded UMBELLIFERAE 160 6 Flowers not umbellate, or ovary 1-celled or more than 2-seeded 7 Pistil 1, the ovary inferior, 1-celled, ultimately 1-seeded; leaves entire, glabrous, exstipulate, somewhat leathery or fleshy; plants root-parasites SANTALACEAE COMANDRA UMBELLATA (L . ) Nutt 7 Pistil 1 or more, the ovary either superior or more than 1-seeded if leaves leathery, entire, and exstipulate; plants not root-parasites 8 Pistil one, 2- to 3-carpellary; ovary 2- or 3- celled, or 1-celled with 2-3 parietal placentae, or 1-seeded but styles or stigmas more than 1 9 Ovary several-seeded; leaves multiform, usually neither fleshy nor rigidly pungent SAXIFRAGACEAE 132 9 Ovary 1-seeded; leaves mostly fleshy, or terete, or rigidly pungent 10 Fruit a circumscissile capsule; flowers subtended by pungent bracts; leaves broadened, usually not succulent AMARANTHACEAE 105 28 10 Fruit indehiscent , the ovary wall usually grown to the seed; flowers generally not subtended by sharp- pointed bracts, but if so the leaves narrow and often terete or rigidly pungent CHENOPODIACEAE 1 0 1 8 Pistils sometimes more than 1, simple, 1-carpellary , the ovary 1-celled and with only 1 placenta; style and stigma 1 ROSACEAE 137 GROUP XV 1 Stamens numerous, monadelphous , forming a tube surrounding the pistil; plants often stellate-pubescent MALVACEAE 154 1 Stamens few or (if numerous) the filaments free or connate only at the base; plants rarely stellate-pubescent 2 Pistils 2 or more, simple 3 Flowers perigynous; leaves usually stipulate 4 Pistils 2 or 3, slightly fused basally; stamens 5-10 SAXIFRAGACEAE 132 4 Pistils more than 3 or stamens more than 10 ROSACEAE 137 3 Flower hypogynous or leaves not stipulate 5 Stamens (4) 5 or 10; pistils (4) 5; fruits follicular; leaves fleshy CRASSULACEAE 131 5 Stamens either more than 10 or fruits other than 5 follicles; leaves rarely fleshy RANUNCULACEAE 111 2 Pistil 1, simple or compound 6 Stamens 15-100; leaves opposite, exstipulate; pistil 3- to 5-carpellary , the placentation not free-central HYPERICACEAE 154 6 Stamens either less than 15 or if that many then either the pistil not 3- to 5-carpellary or the placen- tation free-central 7 Ovary 1-celled (at least near the tip) , often with free-central placentation or with a single seed, never with more than 1 parietal placenta 8 Leaves usually opposite (not all basal) , the nodes often swollen; placentation free-central 9 Sepals 2; petals 5-9 PORTULACEAE 105 9 Sepals usually the same number as the petals) CARYOPHYLLACEAE 107 29 8 Leaves mostly alternate or all basal, the nodes not swollen or the placentation not free-central 10 Stamens more than 10 11 Leaves strongly stipulate; placentation not free- central ROSACEAE 137 11 Leaves not stipulate or if stipulate the placenta- tion free-central PORTULACACEAE 105 10 Stamens 10 or fewer 12 Stamens plainly perigynous ROSACEAE 137 12 Stamens hypogynous 13 Sepals fewer than the petals (if any) , usually 2 or 3, (rarely apparently 4 because of a pair of juxtaposed bracts) PORTULACACEAE 105 13 Sepals mostly more than 2 or 3, usually as many as the petals 14 Ovary 1-seeded 15 Flowers mostly umbellate; perianth parts mostly all alike POLYGONACEAE 97 15 Flowers rarely umbellate; outer perianth parts unlike the inner CARYOPHYLLACEAE 107 14 Ovary several-seeded PORTULACACEAE 105 Ovary more than 1-celled or 1-celled but with 2 or more parietal placentae and several seeds 16 Ovary 2-celled, inferior, each cell 1-seeded UMBELLIFERAE 160 16 Ovary 1- or more-celled, either superior or with more than 1 seed per cell 17 Leaves opposite, entire, the nodes swollen; styles 3-5; stamens 10, hypogynous; calyx strongly gamosepalous (Lychnis, Silene) CARYOPHYLLACEAE 107 17 Leaves, styles, and stamens not at once as above 18 Flowers hypogynous 19 Plants tiny, growing in moist places; leaves opposite, stipulate ELATINACEAE ELATINE TRIANDRA Schkuhr. 19 Plants seldom greatly reduced and mostly not of wet places; leaves often alternate or exstipulate 30 20 Style 1; ovary 4- or 5-celled or 1-celled with 2 parie- tal placentae; anthers sometimes opening by terminal pores 21 Ovary 4- to 5-celled; anthers often opening by terminal pores ERICACEAE 165 21 Ovary 1-celled, with 2 (sometimes intruded) parietal placentae; anthers not opening by terminal pores (Frasera) GENTIANACEAE 169 20 Styles 2-5; anthers not opening by terminal pores 22 Leaves opposite; calyx gamosepalous; fertile stamens 10 (Silene) CAROPHYLLACEAE 107 22 Leaves often alternate; calyx not strongly gamose- palous; fertile stamens 5 or fewer LINACEAE LINUM PERENNE L . 18 Flowers perigynous or epigynous SAXIFRAGACEAE 132 GROUP XVI Ovary partially to wholly inferior; pistil always 1 2 Ovary 1-celled and 1-seeded 3 Stamens mostly 1-3; flowers not borne in involucrate heads VALERIANACEAE 192 3 Stamens 4 or 5; flowers borne in heads surrounded by an involucre of 1 to several series of bracts COMPOSITAE 193 2 Ovary either more than 1-celled or more than 1-seeded 4 Ovary 2-celled, the cells each 1-seeded, readily separating; leaves opposite, stipulate; corolla (3) 4 (5) -lobed (Kelloggia) RUBIACEAE 189 4 Ovary other than 2-celled and 2-seeded; leaves and corolla various 5 Leaves opposite, mostly cauline; stamens 4 (Linnaea) CAPRIFOLIACEAE 190 5 Leaves mostly alternate or all basal; stamens usually 5 CAMPANULACEAE 192 Ovary superior; pistil very occasionally more than 1 6 Anthers opening by terminal pores; ovary mostly 5-celled, many-seeded ERICACEAE 165 31 Anthers not opening by terminal pores; ovary mostly less than 5-celled 7 Sepals 2; corolla regular, the petals usually (4) 5 (6), connate only at the base; ovary 1-celled; placentation free-central PORTULACACEAE 105 7 Sepals and petals usually the same number; corolla mostly strongly gamopetalous , often irregular; ovary diverse 8 Style branches or stigmas 3; ovary 3-celled POLEMONIACEAE 171 8 Style branches or stigmas 1-2; ovary only rarely 3-celled 9 Ovary 2-celled, 4-lobed (at anthesis), usually becoming 4-celled and 4-seeded; fruits ultimately 4 (or by abortion 1, 2, or 3) hardened, 1-seeded nutlets; plants mostly either opposite-leaved and with somewhat squarish stems or harshly pubescent and with the flowers in curled (helicoid) inflorescences 10 Corolla usually regular , (4) 5-lobed; stamens (4) 5; flowers often in helicoid inflorescences; pubescence often harsh; stems not square; leaves mostly alternate BORAGINACEAE 175 10 Corolla usually irregular, mostly bilabiate; stamens mostly 3 or 4 (5); inflorescence not helicoid; pubescence rarely harsh; stems often square; leaves generally opposite 11 Style terminal on the nutlets; stamens 4 or 5; corolla generally only slightly bilabiate; plants mostly not aromatic VERBENACEAE VERBENA BRACTEATA Lag . 11 Style sub-basal on the nutlets; stamens 2 or 4; corolla usually strongly bilabiate; plants often strongly aromatic LABIATAE 178 9 Ovary 1- or more-celled but never developing into 4 nutlets; plants various 12 Stamens as many as the corolla lobes and opposite them, or twice as many; ovary 1- celled, the placentation free-central; corolla regul ar 13 Style and stigma 1; stamens as many as the petals and opposite them; capsule often circumscissile PRIMULACEAE 168 32 13 Styles (or stigmas) 2-5; stamens usually twice as many as the petals; capsule not circumscissile CARYOPHYLLACEAE 107 Stamens fewer than the corolla lobes or as many and alternate with them; ovary not 1-celled and with free- central placentation; corolla often irregular 14 Calyx and corolla 4-lobed regular 15 Corolla scarious, persistent; capsule usually circumscissile; flowers spicate, the spikes ter- minal (the plants scapose) or axillary (such plants oppositely and linearly leaved) PLANTAGINACEAE 188 15 Corolla not scarious , usually deciduous; capsule not circumscissile; flowers rarely spicate; plants seldom scapose 16 Ovary 1-celled and with 2 parietal placentae; plants usually glabrous; corolla mostly twisted in the bud GENTIANACEAE 169 16 Ovary usually 2-celled; plants often pubescent; corolla not twisted in the bud (Veronica) SCROPHULARIACEAE 180 14 Calyx and corolla other than 4-lobed or flowers irregular 17 Corolla usually funnelform, twisted in the bud; leaves alternate, the blades often cordate to hastate; ovary mostly (1~3) 4-seeded, the seeds never hairy; plants often vining CONVOLVULACEAE CONVOLVULUS ARVENSIS L. 17 Corolla generally not funnelform and twisted in the bud, but if so either the leaves opposite, the ovary many-seeded, or the seeds hairy; plants rarely vines 18 Plants usually glabrous; leaves opposite; corolla either rotate and the segments with prominent basal glands or fringed appendages or the lobes more or less twisted in the bud; ovary 1-celled, with 2 parietal placentae GENTIANACEAE 169 18 Plants often pubescent; leaves frequently alternate; corolla lobes neither bearing a basal gland nor twisted in the bud; ovary often 2-celled 33 19 Ovary 1-celled; placentae 2, parietal, sometimes intrusive and nearly contacting, but never actually joined, stamens as many as the corolla lobes (usually 5) HYDROPHYLLACEAE 174 19 Ovary 2 (rarely 4) -celled (or ovaries apparently 2); placentation often axile 20 Fertile stamens usually 2 or 4, if (as rarely) 5 the flower at least slightly irregular SCROPHULARIACEAE 180 20 Fertile stamens 5, the flowers regular 21 Leaves opposite, simple, usually entire; seeds hairy; ovaries apparently 2, the union of the 2 carpels occurring mostly above the ovaries 22 Corolla lobed well over half its length, the lobes reflexed; stamens connate around the style and stigma and joined with them ASCLEPIADACEAE ASCLEPIAS SPECIOSA Torr . 22 Corolla usually lobed less than half the length or else the lobes not reflexed; stamens free or only partially connate, not (or only weakly) joined with the style and stigma APOCYNACEAE 170 21 Leaves mostly alternate (sometimes paired at the nodes but on one side of the stem and thus not truly opposite) , usually not entire; seeds never hairy; ovary 1, the 2 or 3 carpels completely fused SOLANACEAE 180 34 ISOETACEAE Quillwort Family Isoetes L . Quillwort 1 Megaspores (as seen at 40X) with scattered low tubercles, some of which may be confluent into short, low ridges or wrinkles; megaspores seldom over 0.5 mm wide; plants usually amphibious or in shallow water I. BOLANDERI Engelm. 1 Megaspores (as seen at 40X) more or less densely beset with spines or jagged crests or high ridges; megaspores often more than 0.5 mm wide; plants wholly submerged, often in deep water I . LACUSTRIS L. EQUISETACEAE Horsetail Family Equisetum L. Horsetails and Scouring Rushes 1 Aerial stems perennial and evergreen (annual in E. laevi- gatum) , simple, or at least not with regularly whorled branches, never dimorphic; cones spiculate (except often in E. laevigatum); teeth of the sheaths sometimes articu- lated and deciduous , sometimes persistent; stomates generally sunken below the level of the epidermis; sub- genus Hippochaete (Scouring rushes) 2 Stems robust, mostly 2-15 dm tall, (14) 16- to 40-ridged; central cavity more than half the diameter of the stem; teeth articulated to the sheath, but not always deciduous 3 Aerial stems perennial, evergreen; cones distinctly apiculate; sheaths usually with an inframedial or basal black band as well as an apical one, the teeth deciduous or often more or less persistent E. HYEMALE L. 3 Aerial stems annual; cones blunt or inconspicuously apiculate; sheaths black-banded at the tip only, the teeth promptly deciduous E. LAEVIGATUM A. Br. 2 Stems smaller and more slender, mostly 1-3 (5) dm tall, 3- to 12-ridged; central cavity less than 1/3 the diameter of the stem; teeth of the sheath persistent, not articulated E. VARIEGATUM Schleich. 1 Aerial stems annual often dimorphic, usually at least some of them with regular whorls of branches; cones blunt, not apiculate; teeth of the sheaths persistent, not articulated; stomates not sunken; subgenus Equisetum (Horsetails) 35 4 Fertile and sterile stems alike; ridges of the stem smooth or often minutely cross-wrinkled, but without tubercles or spicules; plants fruiting in summer E. FLUVIATILE L. 4 Fertile and sterile stems unlike , the sterile stems green and branched, the fertile ones at first simple and not green, sometimes later green and branched; ridges of the stem often with tubercles or spicules, or merely papillate or almost smooth, but seldom at all cross-wrinkled; plants fruiting in the spring E. ARVENSE L. POLYPODIACEAE Polypody or Common Fern Family 1 Rhizome and leaves with hairs only, lacking scales; sori marginal, confluent, protected by the reflexed leaf margin; petiole stout, erect, with several bundles; spores tetrahe- dral (Hypolepidaceae) PTERIDIUM AQUILINUM (L . ) Kuhn 1 Rhizome (and often the leaves) scaly (the scales sometimes narrow, but distinctly flattened) , often hairy also; other characters various, but not combined as above 2 Petiole with a single bundle, always slender, very often dark and wiry; indusium formed by the reflexed leaf margin, or none; spores tetrahedral (Pteridaceae) CRYPTOGRAMMA CRISPA (L . ) R.Br. 2 Petiole with 2 or more bundles (at least toward the base), sometimes slender and dark as in the foregoing group, more often stouter and paler; sori laminar, with or with- out indusium, the indusium not formed from the reflexed leaf margin; spores bilateral 3 Indusium none, the sori naked (Woodsia, with the indusium often wholly concealed and thus easily overlooked, is keyed here as well as in the following group) 4 Leaves relatively large, 2-8 dm long, forming a vaselike tuft; persistent petiole-bases closely appressed, coarse, flattened, 3 mm wide or more ATHYRIUM FELIX-FEMINA (L . ) Roth 4 Leaves smaller, up to 3 . 5 dm long, not forming a vaselike tuft; persistent petiole-bases free-standing, more slender and wiry, not more than about 2 mm wide WOODSIA 36 3 Indusium present, though sometimes inconspicuous or soon deciduous (Aspidiaceae , in main part) 5 Indusium elongate, flaplike, sometimes with a curved distal end but not at all reniform , opening toward the midvein ATHYRIUM FELIX -FEMINA (L . ) Roth 5 Indusium otherwise 6 Indusium peltate, with a central stalk, opening all around; leaves evergreen, often with pungent teeth POLYSTICHUM 6 Indusium otherwise; leaves variously evergreen or deciduous, but not pungently toothed 7 Indusium hoodlike, attached at the basiscopic side of the sorus, its free tip arched over the sorus and commonly thrown back as the sorus expands; leaves scattered or in small clusters, not accompained by conspicuous, persistent old petiole-bases CYSTOPTERIS FRAGILIS (L . ) Bernh 7 Indusium inferior, platelike, with radiating, com- monly hairlike segments, often wholly hidden beneath the sorus; leaves tufted, accompanied by conspicuous, persistent, wiry old petiole-bases WOODSIA Polystichum Roth Sword Fern 1 Pinnae undivided (though often oblique at the base and with a projecting basal lobe on the acroscopic side) P. LONCHITIS (L.) Roth. 1 Pinnae, or some of them, conspicuously cleft (more than halfway to the midrib) or again pinnate, at least towards the base P. SCOPULINUM (D.C.Eat.) Maxon Woodsia R . Br. 1 Blade glabrous or merely glandular W. OREGANA D.C. Eat. 1 Blade glandular and with glandless, septate hairs, at least on the lower side W. SCOPULINA D.C. Eat. 37 CUPRESSACEAE Cypress Family Juniperus L . Juniper 1 Leaves in 3's, all linear-lanceolate and more or less needle-like or awl-like, 5-19 mm long, pungent, not glandular on the dorsal surface, jointed at the base of free portion; plants mostly decumbent, ours rarely if ever over 2 m tall J. COMMUNIS L. 1 Leaves in 2's or 3's, sacle-like (only the juvenile leaves awl-like, and then only 5-7 mm long), often glandular on the dorsal surface, not jointed at the base of the free portion; plants often erect and over 2 m tall J . SCOPULORUM Sarg . PINACEAE Pine Family 1 Leaves borne in clusters of 2-5 along the main branches, or numerous and in apparent whorls on short lateral spur shoots PINUS 1 Leaves borne singly, spirally arranged along the branches 2 Young branches smooth where the needles have fallen, the leaves deciduous at the base, the scar itself often in a slight crater; cones either stiffly erect and shed scale by scale; or partly or wholly pendent and with a prominent 3-lobed bract protruding past each ovulifer- ous scale; needles mostly flat and blunt, retained on the cut branches indefinitely 3 Cones erect, shed scale by scale (old whole cones non-existent); leaf scar almost or quite orbicular; dormant terminal buds more or less rounded, not at all sharp; branchlets regularly paired and opposite, on the whole the branching very uniform, only an occasional branch unpaired ABIES LASIOCARPA (Hook.) Nutt . 3 Cones in part or entirety pendent, shed whole (old cones usually lying under the tree); leaf scar trans- versely elliptic-oval; dormant terminal buds sharp- pointed; branchlets in part alternate or imperfectly paired as well as opposite, on the whole the branch- ing somewhat irregular PSEUDOTSUGA MENZIESII (Mirb . ) Franco . 38 2 Young branches rough where the needles have been shed, the leaves deciduous above the base which per- sists as a small protuberance; cones not stiffly erect, shed entire but without a prominent bract extending past each scale; needles often square in section and often pungent, deciduous in a few days from the cut branches PICEA Picea A. Dietr. 1 Young branches usually pubescent; needles nearly or quite as thick as broad, 4-angled, the white stripes of stomata nearly equally broad on the upper and lower surfaces; cones 4-5 (rarely to 6) cm long, the scales somewhat pointed and more or less rhomboid in shape P . ENGELMANNII Parry 1 Young branches glabrous; the scales rounded or truncate at the tip P. GLAUCA (Moench) Voss Pinus L . Pine 1 Needles 2 per fascicle; tip (umbo) of the ovuliferous cone scales ending in a sharp, hard prickle P . CONTORTA Dougl . 1 Needles 5 per fascicle; tip (umbo) of the ovuliferous cone scales unarmed 2 Cones sessile or subsessile (any stalk not over 1 cm long), (2) 3-25 cm long, the scales thick, woody, sometimes remaining closed; leaves 3-7 cm long; plants alpine or subalpine; seeds much longer than the wing which often adheres to the scale 3 Cones mostly (5) 8-25 cm long, light brown, opening at maturity and shedding the seeds, then falling intact; scales gradually becoming thinnish toward the tip P . FLEXILIS James 3 Cones mostly 5-8 cm long, purple, remaining closed and tardily shedding the seeds at maturity, seldom falling intact from the tree, but usually broken; scales becoming thickened rather than thinnish toward the tip P. ALBICAULIS Engelm. 2 Cones stalked (the stalk 1-7 cm long), (10) 15-25 cm long, the scales thin, always opening to shed the seeds; leaves 5-10 cm long; seeds much shorter than the wings which remain attached to the seed P . MONTICOLA Dougl . 39 JUNCAGINACEAE Arrow-grass Family Triglochin L . Arrow-grass 1 Carpels and stigmas 3; fruit linear-clavate, the axis 3- winged, the carpels subulate at the base T. PALUSTRE L. 1 Carpels and stigmas usually 6; fruit oblong or ovoid- prismatic, the axis terete, the carpels not subulate at the base 2 Ligules entire or only slightly bilobed, (1) 1.5-5 mm long; blades somewhat obcompressed, mostly 1.5-2.5 (4) mm broad; plants usually at least 3 dm tall T . MARITIMUM L . 2 Ligules deeply bilobed 0.5-1 mm long; blades almost terete, 0.5-1 (1.5) mm broad; plants often less than 3 dm tall T . CONCINNUM Davy POTAMOGENTONACEAE Pondweed Family Potamogeton L. Pondweed 1 Submersed leaves with stipules adnate to the base of the leaf and forming a sheath around the stem, the leaf blades thus not attached directly at the nodes 2 Submersed blades 3-8 mm broad, minutely serrulate- spinulose toward the tip, closely crowded on the stem, very finely 20- to 35-nerved P. ROBBINSII Oaks 2 Submersed blades all less than 3 mm broad, entire, usually not crowded on the stem, mostly 1- or 3-nerved 3 Stigma sessile, the fruit not beaked; sheaths at least partially closed unless mechanically ruptured, remaining around the subtended stem; stems branching below but largely unbranched above P. FILIFORMIS Pers. 3 Stigma borne on a very short style which persists as a tiny beak on the fruit; sheaths open at the base; stems usually dichotomously branching to near the tips P. PECTINATUS L. 1 Submersed leaves with stipules free of the rest of the leaf, the leaf blades or petioles attached at the nodes of the stem 40 4 Leaves all more or less cordate and clasping at the base, submersed, rarely less than 10 (to 30) mm broad 5 Stems often zigzag; stipules usually persisitent, mostly at least 3 cm long, whitish; leaves generally no less than 10 cm long, often more than 2 cm broad; peduncles 1-3 dm long; achenes 4-5 mm long P. PRAELONGUS Wulf. 5 Stems rarely at all zigzag; stipules quickly disint- grating into fibers 1-2 cm long; leaves rarely as much as 10 cm long or 2 cm broad; peduncles mostly less less than 2 dm long; achenes rarely over 3.5 mm long P. RICHARDSONII (Bennett) Rydb . 4 Leaves not cordate and clasping at the base, often dimor- phic, the submersed ones often less than 10 mm broad 6 Leaves less than 3 mm broad, all submersed, linear 7 Stipules firm, strongly fibrous, the fibers free at the stipule tips as prominent cilia 2-3 mm long, persis- tent as the rest of the stipule rather quickly disinte- grates P. FIBRILLOSUS Fern. 7 Stipules delicate, not notably fibrous, tending to be completely deciduous rather than persistent as fibers P. FOLIOSUS Raf. 6 Leaves in part more than 4 mm broad, often dimorphic, the broader ones generally floating 8 Submersed leaves very narrowly linear, mostly less than 2 mm broad and over 10 cm long; floating leaves (if any) rounded to cordate at base P . NATANS L . 8 Submersed leaves either more than 3 mm broad or less than 10 cm long; floating leaves mostly acute at base 9 Stipules less than 3 (in P. alpinus sometimes more than 3) cm long; submersed leaves sessile 10 Floating leaves (if any) not markedly differ- ent from the submersed, the latter (5) 7-20 cm long; plant in general reddish-tinged P . ALPINUS Balbis 10 Floating leaves markedly dissimilar to the submersed, the latter often less than 7 cm long; plant greenish P . GRAMINEUS L . 9 Stipules in part at least 3 cm long; submersed leaves often petiolate P. NODOSUS Poir. 41 JUNCACEAE Rush Family 1 Seeds 3; leaves with closed sheaths, the blades often with long straight marginal hairs LUZULA 1 Seeds numerous; leaves with mostly open sheaths, the blades rarely at all hairy JUNCUS Juncus L. Rush 1 Inflorescence apparently lateral, the lowest (involucral) bract thereof terete, erect, and seemingly a continuation of the stem 2 Flowers usually 1-4 (6-7) per stem; plants alpine (or subalpine); involucral bract rarely as much as 5 cm long 3 Uppermost of the basal sheaths of the stem with a well-developed blade mostly 2-7 cm long; capsule sometimes acute 4 Capsule refuse; perianth segments acute, 4-5 mm long J . HALLII Engelm . 4 Capsule acute; perianth segments acuminate, 6-7 mm long J . PARRYI Engelm . 3 Uppermost of the basal sheaths bladeless or with a blade scarcely 1 (never as much as 2) cm long; capsule refuse J . DRUMMONDII E . Meyer 2 Flowers seldom fewer than 8 per stem; plants often not not alpine or subalpine; involucral bract usually more than 5 cm long J. BALTICUS Wild. 1 Inflorescence terminal, the involucral bract often flattened or conspicuously channeled on the upper (adaxial) side, obviously not a continuation of the stem 5 Blades laterally flattened, equitant (one margin turned toward the stem) , incompletely septate (the septa not extending all the way across the blade), mostly (2) 3-6 mm broad 6 Seeds 0.8-1 mm long, with a distinct appendage at each end; style mostly about 1 mm long, well exserted from the perianth (very easily fractured); stamens 6 J . TRACYI Rydb . 6 Seeds scarcely 0.5 mm long, merely apiculate (not appendaged) at each end; style rarely as much as 1 mm long; stamens 3 or 6 J. ENSIFOLIUS Wikst. 42 5 Blades not laterally flattened and equitant, either dorsi- ventrally flattened or terete, mostly less than 3 mm broad 7 Leaves septate, terete 8 Capsule tapered almost from the base to a long, slen- der, tardily dehiscent or nondehiscent beak that ex- ceeds the perianth; perianth greenish-brown or tawny, segments narrowly lanceolate, acuminate-subulate; stems often arising from slender rhizomes at conspic- uously swollen, more or less fusiform nodes 9 Stamens mostly 3; heads (2-3) 5-30 (50); capsule usually dehiscent to the tip; rhizomes lacking or very short J . TWEEDYI Rydb . 9 Stamens 6; heads mostly 1-15; capsule rarely dehis- cent through the stylar beak; rhizomes often tuber- ous J. TORREYI Cov. 8 Capsule rather abruptly narrowed above, dehiscent through the stylar beak, if any; perianth often deep brownish or brownish-purple, the segments mostly acute to acuminate, but rarely somewhat subulate; rhizomes, if any, never tuberous 10 Stamens 3, the anthers much shorter than the filaments; perianth segments acuminate and often subulate, greenish to brown (but never deep brownish-purple); heads 3 to many J . TWEEDYI Rydb . 10 Stamens usually 6, the anthers often equalling or longer than the filaments; perianth segments often blunt, or deep brownish-purple; heads sometimes only 1 or 2 11 Heads one, or at most (and very rarely) two, more than 12-flowered; perianth deep brown; anthers rarely more than 2/3 as long as the fila- ments; capsule slightly obovoid, the valves broadened above midlength and then abruptly rounded to almost truncate, the tip often slightly retuse; plants mainly montane to alpine J . MERTENSIANUS Bong . 11 Heads (2) 3-many, mostly with less than 12 flowers; perianth sometimes light brown; anthers more than 2/3 as long as the filaments (usually at least as long); capsule usually cylindric or at least not thickened above midlength, the valves 43 nearly oblong, gradually rounded to acute at the tip; plants often of the lowlands J. NEVADENSIS Wats. 7 Leaves not septate, either more or less dor siventrally flattened or semi-terete but with a flat or grooved surface facing the stem 12 Seeds appendaged at each end, about 1 mm long or longer 13 Capsule retuse; anthers scarcely 1 mm long J. HALLII Engelm. 13 Capsule rounded to acute; anthers usually at least 1 mm long J. REGELII Buch. 12 Seeds unappendaged (sometimes because of immaturity) or with only short appendages and less than 1 mm long 14 Flowers in heads; perianth segments usually minutely roughened dorsally J. LONGISTYLIS Torr. 14 Flowers born singly in panicles or umbels, but not in heads; perianth segments not roughened dorsally 15 Flowers 1-10, very short pedicellate; capsule retuse, longer than the perianth J . HALLII Engelm . 15 Flowers often more than 10, or long-pedicellate; capsule not retuse, often shorter than the perianth J. TENUIS Willd. Luzula DC . Woodrush 1 Flowers borne singly (sometimes in 2's) at the end of the branches of an open panicle 2 Stem leaves mostly 2-3 generally 2-3 mm broad; bracts and bracteoles inflorescence finely lacerate-fimbriate; perianth deep purplish-brown; anthers generally about equalling the filaments; plants strongly caespitose but short-rhizomatous; alpine L. PIPERI (Cov.) Jones 2 Stem leaves 2-4 mostly 3-10 mm broad; bracts and bract- eoles mostly erose or only shallowly lacerate and not fimbriate; perianth greenish to purplish-brown; anthers generally shorter than the fillaments; plants not rhizomatous L. PARVIFLORA (Ehrh.) Desv. 1 Flowers borne in one or more semicapitate spikes or in a spikelike panicle 44 3 Inflorescence rather stiffly erect, never drooping, the involucral bract conspicuous, often longer than the inflorescence; seeds 1.4-1.75 mm long, with a whitish, basal, spongy, cellular caruncle up to half as long as the body; anthers from slightly shorter to several times longer than the filaments; plants often of the lowlands L. CAMPESTRIS (L . ) DC. 3 Inflorescence tending to droop, much exceeding the involucral bract; seeds less than 1.4 mm long, the caruncle, if any, much less than half as long as the body; anthers much shorter than the filaments; plants subalpine to alpine L. SPICATA (L . ) DC. CYPERACEAE Sedge Family 1 Achene enclosed or enwrapped in a perigynium, as well as subtended by a scale CAREX 1 Achene not enclosed or enwrapped in a perigynium 2 Style thickened toward the base, the thickened part persistent on the achene as a tubercle which is usually sharply differentiated from the body of the achene ELEOCHARIS 2 Style not thickened, although the achene may have a stylar apiculus 3 Perianth bristles numerous (more than 10), conspic- uous and much elongate ERIOPHORUM 3 Perianth bristles 0-6, in most spp . not exceeding the scales (3 spp. of Eleocharis , with the basal stylar thickening not sharply set off from the body of the achene, might also be sought here) SCIRPUS 45 KEY TO THE CARICES Condensed From Hermann (1970) KEY TO SECTIONS 1 Spikes solitary 2 Spikes androgynous FIRMICULMES C. GEYERI Boott 2 Spikes entirely or very nearly staminate or pistillate ATRATAE 1 Spikes more than 1 3 Stigmas mostly 2; achenes lenticular 4 Lateral spikes short, sessile; terminal spike andro- gynous or gynaecandrous 5 Perigynia not whitish-puncticulate (under a lens) 6 Culms arising singly or a few together from creeping rhizomes DIVISAE 6 Culms cespitose or the rhizomes short-prolonged and with short internodes but not long-creeping 7 Spikes androgynous 8 Perigynia abruptly contracted into a beak 9 Spikes few (generally 10 or less, often greenish); sheaths not red dotted ventrally BRACTEOSAE 9 Spikes numerous, usually brownish or yellowish; leaf sheaths often red dotted at the mouth ventrally PANICULATAE C. DIANDRA Schrank 8 Perigynia tapering to a beak VULPINAE C. NEUROPHORA Mack. 7 Spike gynaecandrous 10 Perigynia without winged margins, at most thin - edged S TELLUL AT AE 10 Perigynia with winged margins OVALES 5 Perigynia whitish-puncticulate (under a lens) not winged margined HELEONASTES 4 Lateral spikes peduncled or, if sessile, elongated} terminal spike staminate, rarely gynaecandrous or androgynous 46 11 Achenes-jointed with the style; perigynia not lustrous 12 Lowest bract long-sheathing; perigynia whitish- pulverulent or golden-yellow at maturity BICOLORES 12 Lowest bract usually sheathless, occasionally short sheathing; perigynia not pulverulent nor golden- yellow at maturity ACUTAE 11 Achenes continuous with the style; perigynia lustrous VESICARIAE Stigmas mostly 3; achenes trigonous 13 Perigynia pubescent, puberulent, or ciliate-scabrous 14 Bracts reduced to bladeless sheaths DIGITATAE C . CONCIANA R . Br . 14 Bracts sheathing or sheathless, the blades well developed 15 Perigynia closely enveloping the achene, strongly tapering at the base; bracts sheathless or nearly so MONTANAE 15 Perigynia not as above or if so the lowest bract strongly sheathing 16 Bracts sheathless or very short-sheathing HIRTAE C . LANUGINOSA Michx . 16 Bracts, at least. the lower ones, long-sheathing FERRUGINAEAE C. LUZULINA Olney 13 Perigynia glabrous 17 Style jointed with the achene, not indurated, at length withering and deciduous 18 Lower bracts long-sheathing EXTENSAE C . VIRIDULA Michx . 18 Lower bracts sheathless or nearly so ATRATAE 17 Style continuous with the achene, indurated, not withering VESICARIAE 47 Divisae 1 Plants dioecious or nearly so; perigynium-beak nearly as long as the body C . DOUGLASII Boott 1 Plants not dioecious, the spikes mostly androgynous; perigynium-beak shorter C. PRAEGRACILIS W. Boott Bracteosae 1 Beak of perigynium only minutely bidentulate, obliquely cleft dor sally, leaf-blades 1-3 mm wide C . VALLICOLA Dewey 1 Beak of perigynium bidentate; leaf blades 1.5-3.5 mm wide C. HOODII Boott Heleonastes 1 Spikes androgynous; perigynia unequally biconvex C. DISPERMA Dewey 1 Spikes (at least the uppermost) gynaecandrous , at least the lower remote; perigynia plano-convex, apiculate to very short-beaked (.25 mm or less); scales hyaline with green center C. CANESCENS L. Stellulatae 1 Perigynium-beak 1/4 to 1/3 the length of the body, shallowl bidentate, its broad teeth very short C. INTERIOR L. H. Bailey 1 Perigynium-beak more than 1/2 to about equal to the length of the body, deeply bidentate C. ANGUSTIOR Mack. Ovales 1 Bracts not leaflike nor conspicuously exceeding the head (except rarely in C. brevior), usually inconspicuous 2 Beak of perigynium slender and terete, sometimes scarcely margined at the tip, the upper 0.25-2 mm of its length little if at all serrulate 3 Perigynia 2.5-6 mm long if longer the scales very dark-colored or spikes in a flexuous or moniliform inflorescence 48 4 Scales shorter and narrower than the perigynia, the perigynia conspicuous in the spikes 5 Perigynia much flattened, thin and scale-like except where distended by the achene 6 Perigynia lightly few-nerved (heavily nerved in a variety of C. microptera) at least at the base ventrally 7 Head oblong-ovoid, the spikes distinguishable; perigynia appressed, the tips inconspicuous, widely margined, ovate, rather abruptly narrowed into the beak; scales dark chestnut to blackish-brown; anthers 1.8-3 mm long C . FESTIVELLA Mack. 7 Head ovoid to suborbicular , truncate at the base, the spikes congested, often scarcely distinguishable; perigynia spreading-ascending , the tips conspicuous in the head, narrowly margined, lanceolate-ovate, usually gradually tapering into the long, slender beak; scales dull brown; anthers 1.3-1.6 mm long C. MICROPTERA Mack. 6 Perigynia nerveless ventrally C. LIMNOPHILA Hermann 5 Perigynia plano-convex, not very thin and scale-like 8 Perigynia conspicuously nerved ventrally C. STENOPTILA Hermann 8 Perigynia nerveless ventrally or very obscurely nerved toward the base C. ILLOTA L. H. Bailey 4 Scales about the same length as the perigynia, concealing them above or nearly so 9 Culms and head stiff, the culms low, usually 1-3 cm high 10 Perigynia oblong-ovate, conspicuously margined, 4-6 mm long; spikes usually 3 or 4; culms more or less roughened above C. PHAEOCEPHALA Piper 10 Perigynia linear-oblanceolate , boat-shaped, very narrowly margined, 3.5-4 mm long; spikes usually 6-8; culms smooth C . LEPARINELLA Mack. 9 Culms slender, taller, usually 2-8 cm high, the head not stiff 11 Culms in small clumps, not leafy, the leaves mostly clustered near the base, their blades ascending ? spikes in a flexuous or moniliform inflorescence, usually not overlapping; perigynia 4.5-6.5 mm long, semi-translucent, glossy C. PRATICOLA Rydb. 49 11 Culms in large clumps, leafy, the leaves covering the lower third of the culms, their blades spread- ing; spikes, except sometimes the lowest, closely approximate; perigynia 4-4.25 mm long, opaque, dull C. PLATYLEPIS Mack. 3 Perigynia 6-8 mm long, the scales light reddish- brown; spikes more or less aggregated into an erect head C. PETASATA Dewey 2 Beak of perigynium flat and margined at the tip, serru- late to the apex 12 Scales shorter than the perigynia, noticeably nar- rower above and largely exposing them C. BREVIOR (Dewey) Mack. 12 Scales almost equalling the perigynia, nearly the same width above and nearly concealing them above C. XERANTHIA L.H.Bailey 1 Bracts either leaf-like or conspicuously exceeding the head C . ATHROSTACHYA Olney Montanae 1 Fertile culms all alike, elongated, 5-40 cm long, bearing both stamate and pistillate spikes; basal spikes absent C. HELIOPHILA Mack. 1 Fertile culms of two types some short, 1-5 cm long, partly hidden among the densely tufted leaf-bases and bearing both staminate and pistillate spikes 2 Perigynia 2.5-3.5 mm long, plump, the beak 0.25-0.75 mm long, shallowly bidentate C. BREVIPES W. Boott 2 Perigynia 3.5-4.5 mm long, more slender, the beak more than 1 mm long, deeply bidentate C. ROSSII Boott Bicolores 1 Mature perigynia whitish-pulverulent, elliptic-obovoid, not fleshy nor translucent, rather obscurely ribbed; scales appressed C. HASSEI Bailey 50 1 Mature perigynia golden-yellow to orange when fully mature or brownish, orbicular obovoid, fleshy, trans- lucent, coarsely ribbed; pistillate scales widely spread- ing at maturity C . AUREA Nutt Atratae 1 Terminal spike not gynaecandrous , in some pistillate or staminate C . HALLII Olney 1 Terminal spike gynaecandrous or staminate 2 Terminal spike staminate 3 Perigynia strongly flattened 4 Leaves of fertile culms widely separate, only the upper 2-4 blade-bearing, the lower sheaths blade- less; culms aphyllopodic and reddish-tinged at the base; leaves of the previous year not persistent or much desiccated at flowering time C. SPECTABILIS Dewey 4 Leaves many on the lower third of the culms; culms clothed at the base with dried leaves of the previous year, not reddish-tinged at the base C. PAYSONIS Clokey 3 Perigynia plump, nearly round or triangular in cross-section, slightly or not at all flattened C . RAYNOLDSII Dewey 2 Terminal spike gynaecandrous, the terminal flowers pistillate 5 Perigynia densely papillose , glaucous-green, trigonous-bi-convex , pistillate scales usually aristate (rarely only cuspidate) , their tips exceed- ing the perigynia C. BUXBAUMII Wahl. 5 Perigynia otherwise; pistillate scales not aristate 6 Perigynia not granular roughened (under a lens), the margins smooth C. HETERONEURA W. Boott 6 Perigynia granular roughened (under a lens) especially on the upper margins, or else the margins cilliate-scabrous below the beak 7 Spikes continguous, sessile or short peduncled, forming a dense head; culms stiff, erect C. ALBONIGRA Mack. 7 Spikes, at least the lowest, strongly peduncled, often distant 51 8 Upper pistillate scales exceeding the perigynia (usually conspicuously so) , copper-brown; lowest peduncle less than half the length of the spike; apex of perigynium- body acute C. HETERONEURA Var. CHALCIOLEPSIS (Holm) Herm . 8 Upper pistillate scales usually exceeded by the perigynia, dark-red to blackish-brown, fading with age; lowest peduncle 1-2 times the length of the spike; apex of perigynium body obtuse C. HETERONEURA Var. BREVISQUAMA Herm. Acutae 1 Perigynia conspicuously veined or ribbed ventrally 2 Perigynia early deciduous , membranaceous, slenderly- nerved, the beak apiculate, entire; lowest bract exceed- ing the culm C . KELLOGGII Boott 2 Perigynia persistent, coriaceous, strongly ribbed, the beak broad, bidentate; lowest bract equalling the inflorescence C . NEBRASKENSIS Dewey 1 Perigynia nerveless ventrally, or with obscure, impressed nerves 3 Perigynia elliptic, broadest below the apex, less than 3 mm long, 1-1.75 mm wide; culms obtusely angled, smooth; usually 1-4 cm long 4 Plants ashy-green; culms 50-100 cm high; leaves rather strongly scabrous; spikes narrowly cylin- dric; scales obtuse, much narrower and shorter than the perigynia 2.4-2.8 mm long, yellowish- green or straw colored C. AQUATILIS Wahl. 4 Plants light or yellowish-green; culms 10-60 cm high; leaves rather smooth, conduplicate , or a spongy consistency; spikes clavate; scales sub- acute, as wide and as long as the perigynia or longer; perigynia 2-2.3 mm long, brownish C. AQUALILIS Var. STANS (Drej .) Boott 3 Perigynia obovate, broadest at the apex, 3 mm or rarely 2.5 mm long, 1.75-2.5 mm wide; culms acutely angled and often scabrous above; spikes 3-10 cm long C. AQUALILIS Var. ALTIOR (Rydb.) Fern. 52 Vesicariae 1 Leaves not conspicuously septate nodulose, 1-7 mm wide; culms ascending, rarely spongy-based, sharply triangu- lar and rough below the spikes; perigynia appressed or ascending; teeth of perigynia long or the perigynia grad- ually long-beaked; lower sheaths fragile, becoming strongly filamentose; ligule much longer than wide; rhizomes without horizontal stolons C . VESICARIA L . 1 Dry leaves conspicuously septate-nodulose, 2-15 mm wide, culms erect, mostly thick and spongy at the base, bluntly triangular below the spikes, smooth; perigynia ascending to squarrose at maturity; teeth of perigynia short or the perigynia abruptly short beaked; lower sheaths not fragile, not becoming filamentose; ligule slightly if at all longer than wide; rhizomes with long, horizontal stolons C . ROSTRA TA Stokes Eleocharis R . Br . Spike Rush 1 Stigmas 3; achenes more or less distinctly trigonous; flowers mostly 2-30 in each spikelet 2 Tubercle confluent with the achene, not forming a distinct apical cap 3 Lowest scale, like the others, subtending a flower; stems slender and short, (0.5) 1-3 (4) dm tall, seldom as much as 1 mm wide, not flattened, not proliferous; spikelets 4-8 mm long, with mostly 3-9 flowers E . PAUCIFLORA (Lightf . ) Link. 3 Lowest scale empty; stems coarser, mostly (2) 4-10 dm tall or more, more or less flattened at least distally commonly 1-2 mm wide, some of them usually proliferous; spikelets (5) 8-13 mm long, with (5) 10-20 (25) flowers E. ROSTELLATA (Torr.) Torr . 2 Tubercle forming a distinct apical cap well differen- tiated from the body of the achene E . ACICULARIS (L . ) R . & S . 1 Stigmas 2, achenes linticular 4 Achenes mostly 1.5-2.5 mm long (tubercle included); anthers mostly 1.3-2.5 mm long; scales mostly 2-4.5 mm long; rhizomatous perennial E. PALUSTRIS (L.) R.& S. 53 4 Achenes mostly 0.5-1.5 mm long; anthers mostly 0.25- 1.0 mm long; scales mostly 1.0-2.5 mm long E. FLAVESCENS (Poir . ) Urban Eriophorum L . Cotton Grass 1 Spikelets 2 or more 2 Midrib of the scale attenuated distally, not reaching the very thin end of the scale; common species E. POLYSTACHION L. 2 Midrib of the scale expanded (or at least not attenuated) distally, reaching the end of the scale; uncommon spp E. VIRIDICARINATUM (Engelm . ) Fern . 1 Spikelet solitary E. CHAMISSONIS C.A.Meyer Scirpus L. Bulrush 1 Well-developed involucral bract solitary, green, leafy or more often erect and resembling a prolongation of the culm, so that the inflorescence appears to be lateral near the tip of the stem rather than truly terminal; smaller involucral bracts sometimes present, but scalelike and not chlorophyllous 2 Spikelets solitary or few (up to 10 or seldom 15), sessile in a sessile cluster 3 Bract solitary; culms very sharply triquetrous, with notably concave sides; achenes 1.5-2.5 mm long and 1.4-1.7 mm wide S. OLNEYI Gray 3 Bracts 2 or 3 , the second and third ones resembling enlarged scales of the spikelet, but not subtending flowers; culms not very sharply triquetrous, the sides plane to slightly concave or slightly convex; achenes 2.2-3.3 mm long and 1.6-2.3 mm wide S . AMERICANUS Pers . 2 Spikelets more or less numerous in a branching inflorescence, often sessile in clusters at the ends of branches; culms terete S . ACUTUS Muhl. 1 Well-developed involucral bracts 2 or more, very unequal, but green, leafy-textured, and more or less spreading, the inflorescence thus evidently terminal S . MICROCARPUS Presl. 54 GRAMINEAE KEY TO THE GENERA 1 Spikelets shed as a unit, the glumes not persistent on the plant (rarely lacking), the point of disarticulation usually just below the glumes, but not rarely along the rachis or the branches thereof GROUP I 1 Spikelets disarticulating above the glumes, the empty glumes persistent on the plant 2 Ligules mainly a fringe of hairs, sometimes with a membranous base but the terminal fringe at least as long as the membranous portion GROUP II 2 Ligules mainly or entirely membranous, often ciliate, erose, or lacerate, but any fringe shorter than the membranous portion 3 Sheaths closed at the base for at least one-fourth their length or leaf tips hooded or prow-like (rather than flat) 4 Leaves folded in the bud, the tips usually prow- like; lemmas unawned POA 4 Leaves rolled in the bud, the tips not prow-like (but flat and pointed); lemmas sometimes awned 5 Lemmas unawned, prominently nerved, the nerves not converging at the tip of the lemma GLYCERIA 5 Lemmas either awned or obscurely convergent- nerved (or both) 6 Culms bulbous-based MELICA 6 Culms not bulbous-based 7 Upper two to four florets sterile and repre- sented by empty lemmas that enfold one another; auricles lacking; sheaths often closed their full length; plants perennial MELICA 7 Upper one or two florets sometimes sterile but the lemmas not enfolding one another, a palea present in each; auricles sometimes present; sheaths never closed their full length; plants sometimes annual 55 Lemmas keeled on the back, never bifid at the tip, often with a cobwebby callus , never awned POA 8 Lemmas rounded on the back, often bifid at the tip, not cobwebby on the callus , often awned BROMUS 3 Sheaths closed for less than one-fourth their length (usually open the full length); leaf tips flat (rather than hooded or prow-like) 9 Spikelets sessile or subsessile in spikes, either turned to one side of the rachis or in two rows on opposite sides of it; spikes either single and terminal (if so the leaves often with auricles), or more than one and racemose or digitately arranged GROUP III 9 Spikelets pedicellate (although often very shortly so) in open to contracted panicles, the panicles (when contracted and pseudospicate) obviously bearing the spikelets all the way around the main axis 10 Spikelets 1-flowered GROUP IV 10 Spikelets 2- to many-flowered 11 Spikelets 2- or 3-flowered, the uppermost flower perfect and with both a lemma and a palea, the lower flowers either staminate or sterile, sometimes reduced to small, more or less bristle- like remnants (one of which might readily be mistaken for a prolonged rachilla) 12 Spikelets 3-flowered 13 Lower two florets staminate, the lemmas sometimes awned; fertile lemma membranous; auricles lacking HIEROCHLOE ODORATA (L . ) Beauv. 13 Lower two florets sterile, the lemmas reduced to tiny awnless vestiges; fertile lemma more or less coriaceous; auricles usually present PHALARIS ARUNDINACEA L . 12 Spikelets 2-flowered PHALARIS ARUNDINACEA L . 11 Spikelets 1- to many-flowered, the reduced flowers (if any) either above, or both above and below the perfect ones 56 14 Culms solid; plants strongly rhizomatous perennials; sheaths with long stiff hairs near the throat, the collar usually pilose DISTICHLIS STRICTA (Torr . ) Rydb 14 Culms usually hollow, if (as rarely) solid then the sheaths and throat without long stiff hairs; plants often not rhizomatous 15 Glumes (one or both) longer than the first lemma; lemmas usually awned, the awn arising from the back of the lemma or sometimes from the sinus of a bifid apex, but never from a pointed tip GROUP V 15 Glumes (both) shorter than the first lemma; lemmas usually awnless but sometimes awned from the pointed tip or from near the tip GROUP VI GROUP I 1 Ligules mainly a fringe of hairs, any basal membranous portion shorter than the fringe 2 Spikelets sessile in one to several racemosely or paniculately arranged spikes, borne in two rows on one side of the rachis 3 Culms solid; spikelets articulate above the glumes, the spikes individually deciduous BOUTELOUA GRACILIS (H.B.K.) Lag . ex Steud . 3 Culms hollow; spikelets articulate below the glumes, the spikes not individually deciduous SPARTINA GRACILIS Trin. 2 Spikelets pedicellate in open to contracted panicles, if subsessile the apparent spike single and terminal, the spikelets arising all the way around the rachis 4 Spikelets subsessile in an erect panicle, subtended and usually exceeded by numerous sterile, bristle- like branches SETARIA VIRIDIS (L . )Beauv . 4 Spikelets pedicellate in open panicles, not subtended by bristles PANICUM 1 Ligules mainly membranous, any terminal fringe shorter than the basal membranous portion 5 Spikelets sessile or subsessile in a single terminal spike, borne alternately on opposite sides of the rachis 6 Spikelets on the average two or three per node 57 7 Spikelets all alike, usually two per node SITANION HYSTRIX (Nutt . ) J. G. Smith 7 Spikelets dissimilar, usually 3 per node, the central one sessile and fertile, the lateral pedicellate and usually sterile HORDEUM 6 Spikelets mostly only one per node AGROPYRON Spikelets pedicellate in open to greatly congested panicles or sessile and spicate, but only on one side of the rachis, the spikes more than one 8 Culms solid; plants perennial; spikelets either all sessile or in pairs, one of each pair sessile BOUTELOUA GRACILIS (H.B.K.) Lag. 8 Culms hollow; plants often annual; spikelets often all pedicellate 9 Spikelets pedicellate in open to contracted panicles, not confined to one side of the rachis 10 Spikelets 1-flowered; sterile lemmas absent 11 Glumes awned; panicle contracted, more or less spikelike POLYPOGON MONSPELIENSIS (L.) Desf. 11 Glumes unawned; panicle sometimes open ALOPECURUS 10 Spikelets 3-flowered, the terminal flower perfect, the lower 2 reduced to bristle-like, sterile, vestigial lemmas PHALARIS ARUNDINACEA L. 9 Spikelets sessile or subsessile in spikelike racemes or spikes, confined to one side of the rachis BECKMANNIA SYZIGUCHNE (Steud . ) Fern . GROUP II 1 Spikelets 1-flowered; sterile lemmas lacking SPOROBOLUS CRYPTANDRUS (Torr . ) Gray 1 Spikelets more than 1-flowered, generally with at least two perfect flowers 58 2 Spikelets 3-flowered, the two lower flowers staminate, the uppermost perfect HIEROCHLOE ODORATA (L . ) Beauv. 2 Spikelets 2- to many-flowered, the flowers generally either all perfect or the uppermost staminate or sterile, but rarely the lowest lemma sterile and glume-like 3 Spikelets in racemose or digitately arranged spikes, sessile in two rows confined to one side of the rachis BOUTELOUA GRACILIS (H.B .K.) Lag. 3 Spikelets more or less paniculate DANTHONIA GROUP III 1 Spikes single and terminal, the spikelets not confined to one side of the rachis; auricles often present 2 First glume lacking, the second sometimes very small; spikelets either turned with their edges toward the rachis (rather than flatwise) or confined to one side of the rachis and partially sunken in it LOLIUM PERENNE L . 2 First glume (as well as the second) usually present; spikelets borne alternately on opposite sides of the rachis and flatwise to it 3 Spikelets averaging two and three per node 4 Fertile flowers mostly at least two per spikelet; spikelets usually two per node, all alike 5 Spikelets two at almost all nodes; glumes 1- to 5-nerved, narrow, entire to cleft; spikelets 2- to 6-flowered ELYMUS 5 Spikelets one at many nodes; glumes 3- to 9- nerved, usually more or less lanceolate; spike- lets 3- to 12-flowered AGROPYRON 4 Fertile flowers mostly only one per spikelet; spikelets usually 3 per node, the middle one sessile and perfect-flowered, the lateral pair pedicellate and usually sterile HORDEUM 3 Spikelets averaging one per node 6 Lemmas slightly toothed as well as usually awned, the nerves prominent, nonconver gent; plants annual TRITICUM 59 6 Lemmas not toothed, awnless or awned, the nerves usually rather obscure, converging toward the tip; plants mostly perennial AGROPYRON 1 Spikes usually more than one, the spikelets usually confined to one side of the rachis; auricules lacking SCHEDONNARDUS PANICULATUS (Nutt.) Trel. GROUP IV 1 Glumes equal, longer than the lemma, strongly compressed- keeled, truncately narrowed at the tip and with the midnerve more or less extended into an abrupt point; lemma awnless; spikelets in a cylindric, spikelike panicle; culms sometimes bulbous at base PHLEUM 1 Glumes unequal, or shorter than the lemma, or not strongly compressed-keeled, mostly gradually tapered; lemma some- times awned; spikelets often in open panicles; culms never bulbous at base 2 Lemma hardened, much firmer than the glumes, usually terete to obcompressed , awned; callus sometimes hard and sharp 3 Awn deciduous, bent but mostly not twisted; lemma plump, rarely more than 5 times as long as thick; callus rarely at all sharp ORYZOPSIS 3 Awn persistent, usually twisted as well as bent; lemma mostly at least 6 times as long as thick; callus often hard and sharp STIPA 2 Lemma membranous, usually no firmer than the glumes, more or less compressed, often unawned; callus not hard and sharp 4 Callus with bearding one-fourth as long to as long as the lemma; awned from midlength or below; rachilla prolonged behind the palea as a bristle mostly (0.5) 1-2 mm long; palea well developed, usually subequal to the lemma; glumes 3.5-12 mm CALAMAGROSTIS 4 Callus not bearded or with bearding mostly less than one-fourth as long as the lemma or rarely the beard- ing longer but then the lemma unawned or awned from above midlength; rachilla rarely prolonged as much as 0. 5 mm; palea often less than half as long as the lemma, sometimes lacking; glumes often less than 60 3.5 mm long (Polypogon has spikelets articulate below the glumes, and should separate under the first lead No. 11 in Group I, but this feature cannot readily be detected in fresh material) 5 Glumes 2-3 times as long as the lemma, terminally awned, the slender awn at least as long as the glumes; lemma erose, awned from near the tip POLYPOGON MONSPELIENSIS (L . ) Desf. 5 Glumes often less than twice as long as the lemma, mostly short-awned or awnless; lemma not erose and awned from near the tip 6 Florets short stipitate; rachilla prolonged, bristle- like, about 0.6 mm long; lemma usually with the vestige of a subapical awn; leaf blades 7-15 mm broad; palea subequal to the lemma CINNA LATIFOLIA (Trevir . ) Griseb . 6 Florets not stipitate; rachilla rarely prolonged and bristle-like; leaf blades often less than 7 mm broad? palea often reduced or lacking 7 Lemma mostly terminally awned or awn-tipped, if unawned then considerably longer than the glumes; rachilla not prolonged behind the palea; culms often solid; palea well developed, mostly subequal to the lemma MUHLENBERGIA 7 Lemma unawned or awned from the back, if unawned then often shorter than the glumes; rachilla some- times prolonged; culms never solid; palea often reduced or lacking AGROSTIS GROUP V Spikelets never more than 2-flowered nor more than 1 cm long; one or both lemmas awned 2 Lemmas erose-truncate , awned from (and rounded on) the back; rachilla prolonged DESCHAMPSIA 2 Lemmas acute or bifid, but not erose at the tip, often awned from the sinus, usually keeled on the back; rachilla sometimes not prolonged 61 3 Lemmas bifid at the tip and usually awned from the sinus, but sometimes awnless; rachilla prolonged beyond the second flower TRISETUM 3 Lemmas not bifid at the tip, always awned, the awn mostly from midlength or below; rachilla not prolonged beyond the second flower (it is only rarely that Cala- magrostis will key here, since the spikelets are almost always 1-flowered) CALAMAGROSTIS 1 Spikelets mostly more than 2-flowered or more than 1 cm long; lemmas sometimes unawned 4 Plant a strongly rhizomatous perennial; lemmas awnless, not bifid SCOLOCHLOA FESTUCACEA (Willd.) Link. 4 Plant an annual or a caespitose perennial; lemmas usually awned or bifid 5 Lemmas erose-truncate at the tip, awned from the back DESCHAMPSIA 5 Lemmas acute or bifid at the tip, mostly awned from the sinus, but sometimes awnless 6 Lemmas with an exserted, geniculate awn TRISETUM 6 Lemmas unawned or with a short, straight awn 7 Ligules mostly 0.5-2 (rarely 3) mm long; panicle greatly condensed; blades folded in the bud; rachilla joints glabrous KOELERIA CRISTATA Pers . 7 Ligules (2.5) 3-4 mm long; panicle somewhat open; blades rolled in the bud; rachilla joints bearded TRISETUM GROUP VI 1 Nerves of the lemma 5-7, parallel and not convergent above at the tip of the lemma, usually fairly prominent; lemmas unawned PUCCINELLIA 1 Nerves of the lemma often other than 5-7, tending to con- verge at the tip of the lemma, usually obscure; lemmas often awned 2 Leaf blades folded in their immature state in the innovations; leaves often turned up at the tip and hooded or more or less like the prow of a canoe 62 3 Lemmas unawned; leaf tips usually prow-like; mostly the sheaths glabrous or the plants rhizomatous POA 3 Lemmas often awn-tipped; leaf tips not prow-like; sheaths pubescent; plants never rhizomatous KOELERIA CRISTA TA Pers . Leaf blades rolled in their young state in the innovations; leaf tips pointed, not prow-like 4 Auricles well developed on at least some of the leaves 5 Spikelets paniculate, all pedicellate FESTUCA 5 Spikelets semi-spicate , at least some of them sessile ELYMUS 4 Auricles lacking 6 Plants dioecious, perennial, caespitose; lemmas awnless HESPEROCHLOA KINGII (Wats.) Rydb. 6 Plants mostly with perfect flowers, often rhizomatous; lemmas sometimes awned 7 Spikelets never more than 2-flowered, the rachilla not prolonged beyond the second flower; culms often solid; lemmas not bifid MUHLENBERGIA 7 Spikelets (at least in part) with more than 2 flowers or the rachilla prolonged; culms never solid; lemmas sometimes bifid 8 Lemmas more or less deeply bifid at the tip, the awn (if any) arising from the sinus between the teeth and therefore never truly terminal; ligules rarely higher on the sides than at the back (opposite the throat) 9 Ligules mostly 0.5-2 (rarely to 3) mm long rachilla joints glabrous KOELERIA CRISTATA Pers . 9 Ligules (2.5) 3-4 mm long; rachilla joints bearded TRISETUM 8 Lemmas not bifid, the awn (if any) terminal; ligules often higher on the sides than at the back FESTUCA 63 Agropyron Gaertn. Wheatgrass 1 Plant an annual; spikes ovate-oblong, less than 2 cm long A. TRITICEUM Gaertn. 1 Plant a perennial; spikes usually slender, at least 2 cm long 2 Rhizomes lacking or very poorly developed, the plants bunch grasses 3 Spikelets crowded, at least some of them as much as 4 times as long as the internodes of the rachis, strongly divergent A . CRISTATUM (L . ) Gaertn. 3 Spikelets distant to crowded, rarely over 3 times as long as the internodes of the rachis (exclusive of the awns), not strongly divergent 4 Anthers about (4) 5 (6) mm long; spikelets rather distant, from shorter to only slightly longer than the internodes of the rachis A. SPICATUM (Pursh) Schribn. & Smith 4 Anthers 1-2 (2.5) mm long; spikelets crowded, mostly 2-3 times as long as the internodes of the rachis 5 Rachis tending to disarticulate at maturity; glumes very narrowly lanceolate, mostly 1- to 3- (5) -nerved; lemmas with a widely divergent awn A. SCRIBNERI Vasey 5 Rachis not disarticulating; glumes narrowly to broadly oblong-elliptic, (3) 4- to 7-nerved; lemmas mostly unawned or with a straight (very rarely divergent) awn A. CANINUM (L.) Beauv. 2 Rhizomes present, usually well developed, the plants not bunch grasses 6 Blades normally flat, 5-10 mm broad; lower sheaths usually hirsute-pilose; plants generally not strongly glaucous; awn of lemma (if any) straight A. REPENS (L.) Beauv. 6 Blades normally strongly involute or considerably less than 5 mm broad; lower sheaths generally glabrous or strigillose (sometimes hirsute-pilose); plants often strongly glaucous; awn of lemma, if any, often divergent 64 7 Spikes loose and open, most of the spikelets usually- shorter than the internodes of the rachis; rachilla usually plainly visible; lemmas glabrous or only puberu- lent, never pubescent; anthers about 5mm long; rhizomes short A. SPICATUM (Pursh) Schribn. & Smith 7 Spikes compact, the upper spikelets usually 2 or 3 times as long as the internodes of the rachis; rachilla usually almost concealed; lemmas often pubescent; anthers often less than 5 rum long; rhizomes usually extensive 8 Glumes mostly 5- to 7-nerved, oblong-lanceolate, broadest at or above midlength, shorter than the first lemma, rarely awn-tipped, generally hairy (to glabrous); lemmas usually copiously hairy; lower sheaths finely strigillose to pilose; anthers more than 4 mm long A. DASYSTACHYUM (Hook.) Schribn. 8 Glumes mostly 3- to 5-nerved, lanceolate, tapered from near the base, often as long as the first lemma, frequently awn-tipped, mostly glabrous but sometimes pubescent; lemmas glabrous; anthers mostly 3-4 mm long A. SMITHII Rydb. Agrostis L. Bentgrass 1 Anthers at least 1 mm long A. ALBA L. 1 Anthers less than 1 mm long 2 Palea well developed, usually at least half as long as the lemma 3 Plants usually over 15 cm tall, short-rhizomatous , perennial; panicle (3) 5-10 cm long, more or less open (at anthesis); palea almost as long as the lemma; rachilla vestige 0.1-0.3 mm long A . THURBERIANA Hitchc . 3 Plants often less than 15 cm tall, non-rhizomatous , sometimes annual; panicle 1-6 cm long, often com- pressed at anthesis; palea not over 3/4 as long as the lemma; rachilla vestige often lacking 4 Palea 2/3 - 3/4 as long as the lemma; plant perennial; panicle greatly compressed, scarcely 5 mm broad when pressed A. HUMILIS Vasey 65 4 Palea scarcely half as long as the lemma; plant annual; panicle not greatly compressed, over 5 mm broad when pressed A. ROSSIAE Vasey 2 Palea lacking or poorly developed, never so much as half the length of the lemma 5 Panicle moderately to greatly congested, several times as long as broad when pressed, the branches ascending, usually spikelet-bearing to near the base; plants mostly either alpine or subalpine or with glumes scabridulous over the back A . EXARATA Trin . 5 Panicle relatively loose and open, often not more than 2-3 times as long as broad when pressed, the branches often spreading or spikelet-bearing only above mid- length; plants often not subalpine; glumes rarely scabrous over the back 6 Panicle diffuse, the branches capillary, erect to spreading, rarely branched and never spikelet- bearing below midlength; glumes often acuminate to semi-aristate , mostly about 2.3 (1.8-3) mm long, sometimes scabrous over the back; lemmas sometimes awned A. SCABRA Willd. 6 Panicle often contracted, if diffuse the main branches forked and usually spikelet-bearing below midlength; glumes often much less than 2.3 mm long, not scabrous over the back; lemmas unawned A. IDAHOENSIS Nash Alopecurus L. Foxtail 1 Glumes wooly-silky over their entire surface, 3-4* mm long; anthers 2-2.3 mm long; native perennials with truncate ligules 1-3 mm long, montane (mostly subalpine) A. ALPINUS J.E.Smith 1 Glumes silky to villous, but the pubescence mainly or entirely on the nerves and keel; anthers often less than 2 mm long; the glumes often less than 3 or more than 4 mm long, and the ligules usually acute or more than 3 mm long A . AEQUALIS Sobol. * Measurements are for spikelets near middle of inflorescence 66 Bromus L. Brome-grass 1 Plants annual 2 Lemmas narrowly acute to acuminate, the teeth acuminate to acuminate-aristate , at least 2 mm long; first glume 1-nerved, the second mostly 3-nerved; awns usually at least 12 mm long B. TECTORUM L. 2 Lemmas rounded at the tip, usually shallowly bidentate, the teeth rarely as much as 2 mm long; first glume 3 (5)- nerved, the second 5 (7, 9)~nerved; awns often much less than 12 mm long B . BRIZAEFORMIS Fisch. & Mey. 1 Plants perennial (occasionally flowering the first year) 3 Spikelets strongly compressed; lemmas more or less keeled (rather than rounded) on the back B. CARINATUS Hook. 3 Spikelets not strongly compressed; lemmas rounded (rather than keeled) on the back 4 Plants rhizomatous; lemmas often unawned or with awn-tip 1-2 (4) mm long B. INERMIS Leys. 4 Plants non-rhizomatous; lemmas with an awn usually at least 4 mm long 5 Panicle narrow, contracted, the branches erect, many shorter than the spikelets; first glume usually 1-nerved; lemmas glabrous (rarely) to evenly scabrid-puberulent or pubescent; ligules less than 3 mm long B . ANOMALUS Rupr . 5 Panicle open, the branches usually more or less spreading, mostly longer than the spikelets; first glume generally 3-nerved; lemmas often unevenly pubescent; ligules often well over 2 mm long 6 Lemmas pubescent unevenly, often only along the lateral nerves, the tip glabrous or the lower portion with much longer hairs than the upper; first glume often 1-nerved; panicle open, the branches slender, spreading to drooping B. CILIATUS L. 6 Lemmas pubescent to scabrid-puberulent evenly over the entire surface, except sometimes the margins with longer hairs; first glume 3 (5)- nerved; panicle sometimes with short, stiffly- spreading branches B. ANOMALUS Rupr. 67 Calamagrostis Adans. Reedgrass 1 Awn geniculate, exserted beyond the glume tips by (1) 1.5-10 mm 2 Collar crisp-pubescent; glumes 4-5 mm long; awn strongly geniculate, generally exserted less than 1.5 mm C. RUBESCENS Buckl. 2 Collar glabrous or only scabrid-puberulent , not crisp- pubescent; glumes 5-8 mm long; awn usually not strongly geniculate, mostly exserted at least 1.5 mm C. PURPURASCENS R. Br. 1 Awn straight or sometimes geniculate, but not exserted beyond (not exceeding) the glumes more than 1 mm 3 Awn geniculate, exserted sidewise slightly beyond the glumes; callus hairs usually not half so long as the lemma 4 Collar of at least some leaves crisp-pubescent C. RUBESCENS Buckl. 4 Collar never crisp-pubescent C . KOELERIOIDES Vasey 3 Awn nearly or quite straight, not projecting sidewise out of the spikelet; callus hairs often over half as long as the lemma 5 Callus hairs rarely more than half as long as the lemma 6 Collar hairy, the hairs longer than those of the adjacent blade or sheath C. RUBESCENS Buckl. 6 Collar glabrous or only puberulent, the hairs, if any, no longer than those of the sheath or blade C . KOELERIOIDES Vasey 5 Callus hairs usually at least 3/4 as long as the lemma 7 Panicle relatively congested, rarely over 2 cm broad when pressed, the individual branches erect or ascending, not readily distinguished; glumes mostly 3-4 mm long; blades usually 1.5- 4 mm broad, often involute; callus hairs often only 1/2-3/4 as long as the lemma; awn stout C . INEXPANSA Gray 7 Panicle almost always open, mostly more than 2 cm broad when pressed, the branches tending to spread, rarely obscured; glumes often more than 4 mm long; blades sometimes well over 4 mm broad, usually flat; callus hairs in general almost to fully as long as the lemma; awn delicate C . CANADENSIS (Michx . )Beauv . 68 Danthonia Lam . & DC . Oatgrass 1 Lemmas more or less pilose over the back as well as along the margins; panicle narrow, of (3) 5-10 spikelets, the branches erect, at least after anthesis D. SPICATA (L.) Beauv. 1 Lemmas glabrous over the back, pilose only along the margins and on the callus; panicle often open, of (1) 2-5 spikelets 2 Panicle narrow, the branches and pedicels erect, more or less secund; spikelets mostly (4) 5-10; sheaths usually glabrous D . INTERMEDIA Vasey 2 Panicle open, the branches usually spreading; spike- lets mostly 1-4 (5); sheaths usually pilose (if the inflorescence is at all narrow and congested) 3 Plants mostly over 5 dm tall; spikelets usually more than one, borne on divergent branches; hairs of the collar and throat mostly 1-2 mm long D . CALIFORNICA Boland 3 Plants mostly not over 3 dm tall; spikelets usually single, if more than one, the lower one(s) short- pedicellate and suberect; some of the hairs of the collar and throat usually 3-4 mm long D. UNISPICATA (Thurb.) Munro Deschampsia Beauv. Hairgrass 1 Panicle narrow; glumes usually equalling or exceeding the upper floret; anthers less than 1 mm long D. ELONGATA (Hook.) Munro 1 Panicle usually open, or if narrow the glumes shorter than the upper floret, or the anthers at least 1.5 mm long D. CESPITOSA (L.) Beauv. 69 Elymus L. Wild Rye; Rye Grass 1 Ligules mostly at least 2 mm long; leaf blades usually flat, (5) 8-20 mm broad; spikelets commonly more than 2 at each node of the spike E. CINEREUS Schribn . 1 Ligules rarely if ever as much as 2 mm long; leaf blades often either involute or less than 8 mm broad; spikelets rarely more than 2 per node 2 Glumes narrowly lanceolate, usually broadest some- what below midlength, nearly parallel at the flattened, not strongly indurate base, concealing at least the first joint of the rachilla; lemmas not strongly scabrid- pubescent on the back; awns, if any, mostly straight E. GLAUCUS Buckl. 2 Glumes linear and tapered from the base, or if broadest somewhat below midlength then their bases hardened and not parallel (and thus the first joint of the rachilla exposed); lemmas not long-ciliate, but often very strongly scabrid-pubescent; awns, if any, mostly strongly divergent E. CANADENSIS L. Festuca L. Fescue 1 Panicle generally open, often over 15 cm long; second glume rarely over 4 mm long; lemmas less than 6 mm long; some of the awns equalling or exceeding the lemmas F . OCCIDENTALS Hook . 1 Panicle often narrow to congested, mostly not over 15 cm long; either the second glume over 4 mm long the lemma 6 mm or more, or all awns much shorter than the lemmas 2 Glumes, lemma, and awn averaging about 2.7, 3.5, 4.2 and 1.5 mm respectively; anthers 0.3-1.7 mm long; panicle congested, rarely as much as 10 cm long; blades filiform, the basal rarely up to 10 cm long F . OVINA L . 2 Glumes, lemma, and awn averaging over 2.7, 3.5, 4.2, and 1.5 mm (lemma sometimes unawned); anthers 2-4 mm long; panicle often open or over 10 cm long; blades often over 10 cm long or not filiform 70 3 Plants truly caespitose, not-rhizomatous; basal sheaths firm, greenish (rarely at all red), persistent, not shred- ding into fibers; awns 2-5 (averaging 3.3 mm) mm long F . IDAHOENSIS Elmer 3 Plants usually either decumbent-based or short-rhizoma- tous; basal sheaths first reddish then brown, thin, strongly nerved, ultimately shredding into filiform fibers (the marcescent veins); awns mostly less than 3 (averaging barely 1.5) mm long F. RUBRA L. Glyceria R. Br. Nom . Conserv. Mannagrass 1 Spikelets terete, mostly well over 1 cm long, linear or narrowly oblong in outline, several times as long as thick G. BOREALIS (Nash) Batch. 1 Spikelets mostly flattened, often less than 1 cm long, ovate to broadly oblong, rarely more than 3 times as long as broad 2 Ligules usually closed in front (often split in pressing or drying), the lower ones mostly 1.5-3 mm long; blades generally 2-5 (6) mm broad; plants (2) 3-8 (11) dm tall; glumes ovate, rounded to obtuse, the first 0.7-0.8 (1) mm long; lemmas barely 2 mm long G. STRIATA (Lam.) A.S.Hitchc. 2 Ligules open in front, mostly 3-6 mm long; blades 6-10 (12) mm broad; plants mostly 10-15 dm tall; glumes lanceolate-ovate, mostly acute, the first 0.7- 1.2 mm long; lemmas mostly 2-2.2 mm long G . ELATA (Nash) Jones Hordeum L. Barley; Foxtail Barley; Foxtail 1 Glumes awnlike, 2-6 cm long, the spike (awns included) usually nearly or quite as thick as long; auricles usually developed on some leaves but barely 0.5 mm long H . JUBATUM L . 1 Glumes often broadened at base, never so much as 2 cm long, the spike (including awns) much longer than thick; auricles often entirely lacking 71 2 Plants perennial, rarely less than 3 dm tall, the blades 3-8 mm broad H. BRACHYANTHERUM Nevski 2 Plants annual, often less than 3 dm tall, the blades mostly 2-4 mm broad H. PUSILLUM Nutt . Melica L. Melic grass; Oniongrass 1 Culms not bulbous-based; lemmas often awned or awn- tipped; sheaths and often the ligules closed in front unless mechanically ruptured M. SMITHII (Porter) Vasey 1 Culms bulbous-based; lemmas unawned; sheaths mostly open above 2 Lemmas acuminate, generally pilose-ciliate near the base, 9~13 mm long; sheaths usually closed to the top and the ligule, itself, closed in front; rachilla joints 2-3 mm long; panicle narrow, the branches ascending M. SUBULATA (Griesb.) Schrib 2 Lemmas acute to obtuse, not acuminate, never pilose- ciliate near the base, often less than 10 mm long; sheaths mostly open above; rachilla joints often only 1. 5-2 mm long; panicle often open, the lower branches spreading 3 Culms usually not tightly clustered, but attached from 1-3 cm apart on a rather slender rhizome; lemmas about 7 (6-8) mm long; anther 2-2.5 mm long; usually montane, in meadows or forests or on mon- tane ridges M. SPECTABILIS Schribn. 3 Culm bases tightly clustered on a short thick rhizome; lemmas averaging 9-12 mm long; anthers usually more than 2.5 mm long; more commonly in sagebrush desert M . BULBOSA Geyer Muhlenbergia Schreb. Muhly 1 Spikelets on long slender pedicels in open, spreading panicles that not rarely are 1/3-2/3 the total height of the plant M. ASPERIFOLIA (Nees&Meyer) Parodi 1 Spikelets subsessile or short-pedicellate in contracted (often spikelike) panicles usually less than 1/3 the total height of the plant 72 2 Lemmas neither slenderly awned (sometimes awn-tipped) nor pilose on the lower half (sometimes puberulent or scaberulent); culms solid 3 Sheaths and culms minutely nodulose-roughened; plant a strongly rhizomatous perennial; anthers about 1.5 mm long M. RICHARDSONIS (Trin.) Rydb 3 Sheaths and culms not nodulose-roughened; plant an annual or a more or less stoloniferous (non-rhizomatous) perennial; anthers about 0.5 (0.8) mm long M. FILIFORMIS (Thurb.) Rydb. 2 Lemmas slenderly awned (awn at least 1.5 mm long) or pilose at least on the lower half (or both); culms often hollow M . ANDINA (Nutt . ) A.S.Hitchc. Oryzopsis Michx. Ricegrass 1 Blades 3-7 mm broad, flat, tapered at each end; ligules truncate, scarcely 1 mm long; lemma 6-8 mm long, not pilose-hirsute O. ASPERIFOLIA Michx . 1 Blades less than 3 mm broad or strongly involute, or the ligules acute and much more than 1 mm long; lemma either much less than 6 mm long or else pilose-hirsute 2 Lemma pilose-hirsute; glumes 5-9 mm long O. HYMENOIDES (R.&S.) Ricker 2 Lemma strigose-pubescent; glumes mostly less than 6 mm long O. EXIGUA Thurb. Panicum L. Panic Grass 1 Plants annuals; glumes and sterile lemmas not short pilose P . CAPILLARE L . 1 Plants perennials; glumes and sterile lemma often short- pilose (Including P. thermale) P. OCCIDENTALE Schribn . 73 Phleum L . Timothy Culms usually bulbous-based; panicle usually over 4.5 cm long, less than 1 cm broad when pressed; anthers generally more than 1 . 5 mm long P. PRATENSE L. Culms not bulbous-based; panicle rarely as much as 4 . 5 cm long but often more than 1 cm broad when pressed; anthers mostly 1-1.4 (1.5) mm long P . ALPINUM L . Poa L . Bluegrass Rhizomes present, often very extensively developed 2 Plants partially to completely dioecious, mostly pistillate 3 Uppermost culm leaf usually with much-reduced (or no) blade; lower blades stiff, usually strongly sca- brous; sheaths rarely closed more than 1/3 their length; lemmas often with longest hairs along the marginal nerves and keel; second glume 3.5-5 mm long P. FENDLERIANA (Steud.) Vase 3 Uppermost culm leaf usually with a well-developed blade; lower blades usually rather lax, rarely strongly scabrous except along the margins; sheaths usually closed at least half their length; lemmas variously pubescent or scabridulous but not longer- hairy on the marginal nerves and keel; second glume about 3.5 mm long P. NERVOSA (Hook.) Vasey 2 Plants mostly perfect-flowered 4 Culms strongly flattened, 2-edged; plants strongly rhizomatous; lemmas scantily if at all webbed P. COMPRESSA L. 4 Culms slightly if at all flattened, not 2-edged; plants often either only weakly rhizomatous or with strongly webbed lemmas 5 Panicle narrow, the branches ascending or appresse< lemmas scabrous to pubescent on all the nerves, but not webbed P . ARID A Vasey 5 Panicle open, the branches mostly spreading; lemmas often webbed at base, or glabrous on the internerves 74 6 Plants alpine or subalpine; lemmas pubescent over the back and silky on the 5 nerves, usually webbed P. GRAYANA Vasey 6 Plants often of lower elevations; lemmas sometimes glabrous on the internerves, or not webbed 7 Lemmas not webbed at base, from glabrous over- all or scabrid-puberulent on the keel and marginal nerves only, to finely scabrid-puberulent over the back; sheaths often retrorsely puberulent, closed to well above midlength P. NERVOSA (Hook.) Vasey 7 Lemmas often webbed at base, if not then generally pilose on the keel and marginal nerves, at least 8 Anthers mostly 0.5-0.9 (never over 1) mm long; lower panicle branches mostly in 2's P . LEPTOCOMA Trin . 8 Anthers at least 1 mm long; lower panicle branches usually in 3's to 5's 9 Plants truly rhizomatous, usually not growing in wet places; ligules mostly not over 1.5 (rarely the uppermost up to 3) mm long, truncate; lemmas more than 3 mm long P . PRATENSIS L . 9 Plants stoloniferous but not truly rhizomatous, often growing in wet places; ligules mostly (2) 3-7 mm long, often acute; lemmas 2.5-3 mm long P. PALUSTRIS L. 1 Rhizomes lacking, although plants sometimes stoloniferous 10 Culms usually enlarged and bulbous at base; florets mostly or all modified into small purplish bulblets without stamens or pistil P. BULBOSA L. 10 Culms not bulbous-based; florets not modified into bulblets, but having stamens, a pistil, or both 11 Lemmas with long, tangled, cobwebby hairs at base 12 Lemmas glabrous (except for the basal cobwebby hairs) or pubescent only on the keel P. CUSICKII Vasey 12 Lemmas pubescent on the marginal nerves as well as on the keel 75 13 Panicle loose, the branches slender, the lower ones 1-3 per node, spreading to reflexed; spikelets usually- purplish; ligules glabrous, usually over 1 mm long; anthers not over 1 mm long 14 Lower panicle branches reflexed, 1-3 per node P. REFLEXA Vasey & Schribn. 14 Lower panicle branches usually not reflexed, generally in pairs P. LEPTOCOMA Trin. 13 Panicle often narrow, the branches ascending, or more than 3 per node; spikelets usually greenish; ligules often puberulent-scabridulous , sometimes all less than 1 mm long 15 Spikelets averaging about 6 mm long, the lemmas 4-5 mm long P. GRAYANA Vasey 15 Spikelets usually less than 5 mm long, the lemmas less than 4 mm long 16 Plants of the lowlands or lower mountains, usually where moist; culms decumbent and usually stolonous, (3) 4-12 dm tall; ligules (2) 3-5 mm long P. PALUSTRIS L. 16 Plants montane to subalpine, on moist to open rocky areas; culms erect, not at all stolonous; ligules rarely as much as 2 mm and never so much as 3 mm long 17 Culms usually at least 2.5 dm tall; glumes rarely as much as 3.5 mm long; montane to (sometimes) subalpine P . INTERIOR Rydb . 17 Culms rarely over 2 dm tall; second glume 3.5-4.5 mm long; subalpine to alpine P. PATTERSONII Vasey 11 Lemmas not cobwebby at base 18 Spikelets compressed, at anthesis usually less than twice as long as broad; lemmas rather strongly keeled; plants sometimes dioecious, or all pistillate 19 Lemmas pubescent (usually villous or pilose) on the keel and marginal nerves, or hairy over the entire lower portion, or sericeous, or pilose on the nerves and hairy between 20 Plants almost entirely imperfect-flowered, usually functionally pistillate 76 21 Lemmas long-villous on the keel and marginal nerves (see also P. cusickii which does not have greatly reduced blades on the upper culm leaves and which is pilose on the keel, only); blades stiff; usually strongly scabrous, the uppermost on the culms usually greatly reduced or even wanting; sheaths glabrous or scabrous, rarely closed as much as 1/3 their length P. FENDLERIANA (Steud.) Vasey 21 Lemmas uniformly pubescent, not long-villous on the keel and marginal nerves; blades rather lax, mostly scabrid on the margins, only, the uppermost not greatly reduced; sheaths often puberulent, usually closed at least 1/2 their length P. NERVOSA (Hook.) Vasey 20 Plants mostly perfect-flowered, both the stamens and pistil functional 22 Panicles narrow, contracted, several times as long as broad, but usually not over 6 cm long; plants rarely over 2 m 23 Second glume 3.5-4.2 (averaging almost 4) mm long, subequal (or equal) to the first lemma4, panicle very compact (suggestive of that of Calamagrostis purpurascens) , almost continuous , the pedicels or panicle branches scarcely visible, rarely as long as the spikelets; plants mostly 5-15 (20) cm tall P. PATTERSONII Vasey 23 Second glume 2.5-3.5 (averaging about 3.2) mm long, shorter than the first lemma; panicle more open than that of Calamagrostis purpurascens, the panicle branches and pedicels mostly visible, and some of them longer than the spikelets; plants mostly 10-20 (25) cm tall P . RUPICOLA Nash 22 Panicles either open and with spreading or ascending to drooping branches, or over 6 cm long, or plants much more than 2 dm tall 24 Spikelets 2/3 as broad as long, subcordate; blades flat, 2-4 mm broad, the uppermost below midlength of the culm; ligules coarsely erose, truncate to obtuse, glabrous, (1) 1.5-3 (4) mm long P. ALPINA L. 77 24 Spikelets usually less than 2/3 as broad as long, or oblong rather than subcordate; blades often involute or less than 2 mm broad, the uppermost generally above midlength of the culm; ligules various 25 Ligules usually truncate, 0.3-1.0 (or rarely the longest 1.5-2) mm long; spikelets mostly 2- to 3 (4) -flowered; second glume 2.5-3 (rarely to 3.5) mm long P . INTERIOR Rydb . 25 Ligules usually obtuse to acute, generally at least 1 (the longest 2-4) mm long; spikelets mostly 3- to 5-flowered; second glume rarely less than 4 mm long P . GRAYANA Vasey 19 Lemmas glabrous or scabrous to scabrid-puberulent , not villous or pilose on the keel and marginal nerves and not truly pubescent elsewhere 26 Panicles open, the pedicels evident; sheaths of basal culm leaves often puberulent or reddish- purple, those of the upper part of the culm closed to well above midlength; blades mostly 2-3.5 (5) mm broad; lower ligules truncate, thickish, strongly pubescent, cilate, averaging 0.5-1 mm long; gulmes about 3 and 3.5 mm long, respectively P. NERVOSA (Hook.) Vasey 26 Panicles congested, the pedicels mostly not evident; sheaths of basal leaves rarely either puberulent or reddish-purple, those of the upper part of the culm rarely closed as much as half the length; blades often much less than 2 mm broad; lower ligules often acute, or well over 1 mm long, or not pubescent; glumes tending to average more than 2 and 3.5 mm long P. CUSICKII Vasey 18 Spikelets only slightly compressed, at anthesis over twice as long as broad; lemmas rounded on the back, or only slightly keeled; plants perfect-flowered 27 Ligules thickish, strongly ciliolate, truncate to rounded, those of the innovations and basal culm leaves scarcely visible from the side, mostly not over 0. 5 (to 1) mm long, those of the upper culm leaves mostly 1-1.5 (2, rarely 2.5) mm long P. JUNCIFOLIA Schribn. 78 27 Ligules thin and membranous, rarely ciliolate, usually acute, those of the innovations and lower culm leaves usually over 1 mm long, those of the upper culm leaves mostly 2-7 mm 28 Lemmas scabrous or glabrous, but not crisp-puberu- lent, on the lower half or fourth and sometimes all over P. NEVADENSIS Vasey 28 Lemmas crisp-puberulent on the lower half or fourth or sometimes only at the base, but not scabrous all over 29 Plants greenish, usually over 4 dm tall; spikelets mostly tawny or light green, the lemmas some- times purple-banded but usually not purplish all over; basal leaf blades 1-3 mm broad, usually over 5 cm long P. SCABELLA (Thurb . ) Benth. 29 Plants often more or less reddish-tinged, mostly less than 3, and very rarely over 4 dm tall; spikelets mostly purplish-tinged; basal leaf blades usually filiform and not over 1 mm broad, involute to folded, mostly less than 5, but very rarely up to 8 cm long P. SANDBERGII Vasey Puccinellia Pari. Nom . Conserv. Alkali-grass 1 Nerves of the lemma prominent; plants occurring in fresh water; blades flat, 3-12 (15) mm broad; ligules erose or lacerate, 3-9 mm long P. PAUCIFLORA (Presl.)Munz 1 Nerves of the lemma rather indistinct; plants usually of saline or alkaline soil; blades often involute, mostly less than 3 and rarely over 4 mm broad; ligules entire or subentire, rarely over 3 mm long 2 Lemmas mostly 1.5-1.8 (1.4-2) mm long; anthers 0.5-0.8 mm long; lower panicle branches usually reflexed, spikelet-bearing chiefly near the tip P. DISTANS (L.) Pari. 2 Lemmas mostly more than 2 mm long; anthers often over 0.8 mm long; lower panicle branches often erect, usually spikelet-bearing most of their length P. NUTTALLIANA (Schult.) A.S .Hitchc. 79 Stipa L. Needlegrass; Needle & Thread; Porcupine Grass 1 Glumes 15-40 mm long; lemma 8-25 mm long, the awn usually (6) 10-20 cm long S. COMATA Trin. & Rupr . 1 Glumes less than 15 mm long; lemma mostly less than 8 mm long, the awn rarely over 6 cm long 2 Panicle open, the branches spreading, spikelet- bearing only near the tip; awn rarely as much as 25 mm long S. RICHARDSONII Link. 2 Panicle narrow, the branches ascending to erect, often spikelet-bearing to near the base; awns often over 25 mm long 3 Palea glabrous, less than half as long as the lemma; florets "plump" , 5-6 mm long and nearly 1 mm thick; callus short and not very sharp S . VIRIDULA Trin . 3 Palea either hairy or over half as long as the lemma, or both; florets often more than 6 times as long as thick; callus often slender and sharp S. OCCIDENTALIS Thurb. Trisetum Pers. Trisetum 1 Lemmas awnless or with a short straight awn not over 6 mm long T. WOLFII Vasey 1 Lemmas awned, the awn curved or geniculate T. SPICATUM (L.) Richter 80 SPARGANIACEAE Bur-reed Family Sparganium L. Bur-reed 1 Staminate heads usually single (rarely 2), the anthers 0.3-0.6 (0.8) mm long , at least half as broad; beak of the achene about 1-1.5 mm long; leaves 3-6 (2-9) mm broad S . MINIMUM Fries 1 Staminate heads usually 2 or more, the anthers often more than 0.8 mm long or less than half as broad as long; beak ot the achene much more than 1.5 mm long; leaves often much more than 6 mm broad 2 Stems and leaves generally submersed or floating; leaves mostly less than 5 (to 8) mm broad, not scarious-margined; mature pistillate heads 1-2 cm thick; stigma scarcely 1 mm long; achene beak (including stigma) about 2 mm long S. ANGUSTIFOLIUM Michx. 2 Stems and leaves often over 5 mm broad, somtimes scarious-margined near the base; pistillate heads usually more than 2 cm thick when mature; stigma about 2.5 mm long; achene beak (including stigma) well over 3 mm long (S . Simplex) S . EMERSUM Rehmann TYPHACEAE Cat-tail Family Typha L. Cat-tail 1 Leaves mostly 8-20 mm broad; pollen in tetrads; plants often over 1.5m tall; staminate and pistillate portions of the spike tending to be contiguous; subtending bract usually lacking in the pistillate flowers; stigmas oblanceo- late-obovate; abortive ovaries pyriform T . LATIFOLIA L . 1 Leaves mostly about 5 (3-10) mm broad; pollen grains single; plants rarely over 1.5 m tall; staminate and pistillate portions of the spike not contiguous; subtend- ing bract usually present in the pistillate flowers; stigmas linear; abortive ovaries flattened and more or less cuneate T. ANGUSTIFOLIA L. 81 LEMNACEAE Duckweed Family Lemna L . Duckweed 1 Fronds oblong to lanceolate, 6-10 (12) mm long, many with slender stalks as long as the main body, usually remaining attached together to form large mats, often submersed L . TRISULCA L . 1 Fronds more nearly oval, less than 6 mm long, not long stalked, tending to separate into individual plants or small colonies, floating 2 Thalli averaging less than twice as long as broad, obscurely 3-nerved L. MINOR L. 2 Thalli averaging more than twice as long as broad, 1-nerved L . MINIMA Philippi LILIACEAE Lily Family 1 Perianth in 2 very dissimilar series, either the sepals or the petals with a deep round to oblong gland CALOCHORTUS 1 Perianth in 2 series of essentially similar segments (tepals) , all either gland-bearing or glandless 2 Flowers several to many in a terminal umbel or head on a leafless scape; leaves basal, linear; plants from tunicated bulbs ALLIUM 2 Flowers solitary to racemose or paniculate, never in a single umbel or head on a leafless scape 3 Leaves linear, tough and stiff, persistent year after year in a basal rounded clump, often sharp pointed or with fibrous margins; inflorescence a large raceme or panicle, terminal on an annual stem XEROPHYLLUM TENAX (Pursh) Nutt. 3 Leaves various, but never persistent year after year; inflorescence various 4 Leaves primarily on the flowering stem and mostly above the base, sometimes non basal, usually not strongly reduced upward on the stem 5 Plants from a deep-seated scaly bulb; leaves linear to lanceolate, often whorled; flowers showy, white or yellow to purple, the tepals (12) 20-70 mm long FRITILLARIA 82 5 Plants rhizomatous; leaves scale-like to ovate, never whorled; flowers mostly not showy, the tepals often less than 12 mm long 6 Stem unbranched; flowers 5-10 (20) in terminal raceme or more in terminal panicle SMILACINA 6 Stem usually branched; flowers born along stem 1-2 per node, or 1-4 at the tips of the main branches 7 Flowers 1-several at the tip of the branches of the main stem; leaves usually strongly oblique at the base DISPORUM TRACHYCARPUM (Wats. ) Benth. & Hook. 7 Flowers 1 or 2 per node along the lower side of the stem; leaves usually slightly or not at all oblique STREPTOPUS AMPLEXIFOLIUS (L.) DC. Leaves primarily basal, the flowering stem naked or with leaves greatly reduced upward 8 Styles 3, distinct almost to the ovary; flowers some- times perigynous 9 Leaves 2-ranked and more or less equitant; plants rhizomatous; tepals 2.5-6.5 mm long; pedicels usually in 3's, each with 3 separate to strongly connate bracteoles near the tip; pollen sacs not confluent; stamens hypogynous TOFIELDIA GLUTINOSA Michx. 9 Leaves not 2-ranked or equitant; plants with a bulb; tepals often more than 6.5 mm long; pedicels usually single and not bracteolate near the tip; pollen sacs confluent; stamens often perigynous ZIGADENUS 8 Styles 1, or 3 but connate more than half the length; flowers nearly or quite hypogynous 10 Leaves several, linear, at least 10 times as long as broad; flowers mostly 10 or more in a bracteate raceme, regular to irregular CAMASSIA QUAMASH (Pursh) Greene 10 Leaves mostly 2, lanceolate or oblong to oblanceo- late, less than 10 times as long as broad; flowers 1-5, regular ERYTHRONIUM GRANDIFLORUM Pursh 83 Allium L. Wild Onion; Wild Garlic 1 Inflorescence subcapitate, flowering from the center out- ward; leaves cylindrical, hollow A . SCHOENOPRASUM L . 1 Inflorescence subumbellate , flowering from the outside inward; leaves solid, flat or channeled, rarely terete 2 Bulb coats persisting as reticula of coarse anastomosing fibers; ovary crested with 6 low knobs 3 Leaves usually 2 per scape; tips of inner perianth segments spreading; flowers usually white A . TEXTILE Nels . & MacBr . 3 Leaves usually 3 or more per scape; tips of inner perianth segments erect; flowers usually pink some- times replaced by bulbils A. GEYERI Wats. 2 Bulb coats without fibers or with parallel fibers, never fibrous-reticulate 4 Bulbs elongate, terminating stout primary rhizomes or only stipitate (short-rhizomatous) ; outer bulb coats striate with elongate cells in regular vertical rows 5 Bulbs from stout Iris-like rhizomes; umbel erect; ovary crestless; stamens often included in perianth A. BREVISTYLUM Wats. 5 Bulbs merely stipitate (often obscurely so); umbel nodding; ovary conspicuously crested with 6 thin processes; stamens exserted A . CERNUUM Roth 4 Bulbs ovoid to subspherical; rhizomes, if present, slender and secondary; outer bulb coats often cellular-reticulate A. BRANDEGEI Wats. Calochortus Pursh Sego Lily 1 Ovaries and fruits orbicular to oblong, 3 winged; basal leaf broad and flat C . EURYCARPUS Wats . 1 Ovaries and fruits linear, triangular in section, but not winged; basal leaf linear , concave-convex, channeled C . GUNNISONII Wats . 34 Fritillaria L. Fritillary 1 Flowers yellow, fading to red or purplish; style one, the stigma discoid F. PUDICA (Pursh) Spreng. 1 Flowers purplish, often more or less mottled; styles 3, connate only near the base, the stigmas 3 F . ATROPURPUREA Nutt . Smilacina Desf. False Solomon's Seal 1 Flowers paniculate, scarcely 3 mm long; stamens exceed- ing perianth S. RACEMOSA (L . ) Desf. 1 Flowers usually simple racemose (very rarely the raceme compound near the base), usually 4-7 mm long; stamens shorter than perianth S. STELLATA (L.) Desf. Zygadenus Michx. Death Camas 1 Tepals 8-11 mm long not clawed, the gland obcordate; stamens perigynous, the ovary 1/4-1/3 inferior Z. ELEGANS Pursh 1 Tepals less than 7 mm long, at least the inner series clawed, the gland broadly ovate; stamens hypogenous, the ovary superior Z . VENENOSUS Wats . IRIDACEAE Iris Family 1 Perianth segments essentially similar; style branches slender, not at all petaloid SISYRINCHIUM ANGUSTIFOLIUM Mill. 1 Perianth segments dissimilar, the outer the more showy, usually spreading to reflexed; style branches petaloid IRIS MISSOURIENSIS Nutt. 85 ORCHID ACEAE Orchid Family Plant without green leaves when in flower, often white, reddish-brown, or very pale yellow 2 Spur well developed; underground parts of the plant neither profusely branched nor coral red HABENARIA 2 Spur lacking or very short and merely saccate; under- ground parts of the plant often profusely branched and coral red 3 Perianth segments not connate into a hood, yellow to pink, brownish-red, or purple; roots much- branched, reddish CORALLORHIZA 3 Perianth segments connate into a long hood, white or cream; roots fleshy, fascicled, neither much- branched nor reddish SPIRANTHES ROMANZOFFIANA Cham . Plants with at least one green leaf when in flower 4 Base of the lip forming a well-developed, saccate to slender spur HABENARIA 4 Base of the lip not forming a spur 5 Flowers 1 or very occasionally 2; lip saccate; plant with a subglobose corm and a single leaf CALYPSO BULBOSA (L . ) Oaks 5 Flowers usually several to many, the lip either not saccate or the plant with several leaves 6 Leaves 1 or 2, either basal or near midlength of the stem; plants often cormose at the base LISTERA 6 Leaves usually more than 2, alternate or basal; plants not cormose at the base 7 Leaves basal and rosulate, usually somewhat mottled, persistent; plants rarely in swampy area, the roots neither fleshy nor fascicled GOODYERA OBLONGIFOLIA Raf . 7 Leaves cauline, alternate, not mottled, non- persistent; plants usually in wet to swampy areas, the roots fleshy and fascicled SPIRANTHES ROMANZOFFIANA Cham . 86 Corallorhiza Chat. Coral Root 1 Sepals and petals pinkish, prominently 3 (4- to 5) -striped with reddish-brown or purple, the sepals (7) 10-17 mm long; lip unlobed; spur lacking C . STRIATA Lindl . 1 Sepals and petals yellow or pink to wine-red, not striped although often lightly red-veined, the sepals often less than 10 mm long; lip often lobed; spur often present 2 Sepals (4.5) 5 (6) mm long, yellow or greenish-yellow to nearly white (seldom purplish-tinged) , 1-nerved; lip toothed-lobed near the base C . TRIFIDA Chat. 2 Sepals 6-13 mm long, often reddish, usually 3-nerved; lip sometimes not lobed 3 Lip neither laterally-lobed nor -toothed; sepals 6-8 mm long C . WISTERIANA Conrad 3 Lip usually laterally-lobed or -toothed; sepals (6) 8-10 (13) mm long 4 Column slender, mostly 6-7 (8) mm long; spur usually with a free tip 1-3 mm long; lip with no more than 1 or 2 spots C. MERTENSIANA Bong. 4 Column stout, 3.5-4.5 (5) mm long; spur generally lacking, or reduced to a small gibbosity at the top of the ovary; lip usually with several spots C. MACULATA Raf. Habenaria Willd. Rein Orchid 1 Leaves all on the lower third of the stem, often truly basal, the plants scapose, the greater length of the flowering stem merely with 1-several greatly reduced bracts; flowers predominantly greenish 2 Sepals 1-nerved; leaves 1-5, always at least 5 times as long as broad together on the lower 1/3 of the stem but not all basal, tending to wither by anthesis; flowers subsessile, without obvious pedicels; lip less than 6 mm long; plants mostly of dry areas H. UNALASCENSIS (Spreng)Wats . 37 2 Sepals 3- to many-nerved; leaves 1-2 (rarely 3), less than 5 times as long as broad, basal, not withering by anthesis; flowers with evident pedicels (1) 2-7 mm long; lip (4) 5-20 mm long (if less than 6 mm long the basal leaves 1 or at most 2); plants usually in moist areas H. OBTUSATA (Banks) Richards. 1 Leaves several to many, all cauline, the stems leafy most of their length; flowers often white 3 Sepals 1-nerved; stems leafless and not leafy-bracteate above the middle H. UNALASCENSIS (Spreng . ) Wats. 3 Sepals 2-nerved, the lateral nerves sometimes obscure; stems leafy or leafy-bracteate above the middle 4 Spur scrotiform, much enlarged near the tip where somewhat didymous, scarcely at all curved, usually less than 2/3 as long (rarely nearly as long) as the lip; flowers greenish; lip narrowly oblong to ellip- tic, rounded to obtuse; raceme usually open H. SACCATA Greene 4 Spur linear to clavate, rarely if ever at all scrotiform, generally slightly to strongly curved, if less than 2/3 as long as the lip then the flowers white and the lip usually considerably widened near the base; lower- most cauline leaves often acute; raceme mostly rather congested 5 Flowers white or only pale greenish; lip rhombic- lanceolate or -oblong, considerably broadened just above the base and usually abruptly narrowed to a lanceolate or (commonly) narrowly oblong distal half, usually cellular-serrulate along the margin; spur from shorter than the lip to almost twice as long, only slightly or not at all clavate H. DILATATA (Pursh) Hook. 5 Flowers greenish; lip lanceolate to linear, some- times broadened at the base but not rhombic, the margin not cellular-serrulate; spur rarely any longer that the lip, but if longer then usually strongly clavate H. HYPERBOREA (L . ) R.Br. 88 Listera R .Br . Twayblade 1 Lip cleft about half the length into 2 linear-lanceolate, somewhat divergent lobes; leaves subcordate; column and anther scarcely 1.5 mm long L. CORDATA (L . ) R.Br. 1 Lip rounded to refuse or only shallowly bilobed, the lobes broad and rounded; leaves rarely at all cordate; column and anther usually at least 2 mm long L. CAURINA Piper SALICACEAE Willow Family 1 Flowers individually subtended by an obliquely cup- shaped disk, but without obvious glands; leaf buds covered by several scales, stamens 6-many; scales subtending the flowers laciniate or fimbriate, subentire; trees with pendulous catkins POPULUS 1 Flowers lacking a disk but provided with one or two enlarged basal glands; leaf buds covered by a single scale; stamens typically 2, sometimes 5-8 or only 1; scales subtending the flowers entire or occasionally somewhat toothed; trees or more often shrubs, with erect or sometimes pendulous catkins SALIX Populus L . Poplar 1 Smooth-barked tree; buds shiny but not resinous; bracts more or less persistent, deeply few-lobed and conspicuously long-white-hairy; stamens 6-14; capsules narrow and small, lanceolate or lance-ovate, 4-6 mm long, 2-carpellate; stigmas slenderly lobed; petioles strongly flattened laterally; leaves not distinctly carti- laginous-margined; plants not confined to streambanks and lakeshores P. TREMULOIDES Michx. 89 1 Rough-barked trees; buds resinous; bracts deciduous at anthesis, laciniate-fringed but otherwise glabrous or only inconspicuously short-hairy; stamens 12-60 or more; capsules mostly larger and relatively broader, 2- to 4- carpellate; stigmas broadly dilated, with irregular mar- gins; petioles and leaves various; plants largely confined to streambanks and lakeshores 2 Leaf blades mostly 2-5 times as long as wide, with cuneate base (base rounded on large leaves or vigor- ous young shoots), on petioles up to a third as long; carpels 2 P . ANGUSTIFOLIA James 2 Leaf blades mostly 1.4-2 times as wide, with broadly cuneate to rounded-ovate base, on petioles 1/3-3/5 as long; carpels 2-3 3 Leaf blades green beneath not glaucous P . ACUMINATA Rydb . 3 Leaf blades glaucous beneath, dark green above P . BALSAMIFERA L . Salix Willows Taken From Dorn (1970) 1 Trees, usually with one main trunk at the base; 2 Leaves green beneath (rarely glaucous); glandular processes on petiole near base of leaf blade S . LASIANDRA Benth. 2 Leaves glaucous or much lighter beneath than above; glandular processes usually absent 3 Leaves mostly widest at about the middle; mature buds usually with depressed margins; bark of older twigs cracked giving white-streaking appear- ance; catkins on leafy peduncles; pedicels 2-5 mm long; habitat various S . BEBBIANA Sarg . 3 Leaves mostly widest above the middle, often round at the tip; buds and twigs usually not as above; freshly stripped bark of living twigs of previous year usually with a "skunky" odor; catkins sessile or nearly so; pedicels 1-2 mm long; most common drier locations in upland forests, and burned-over areas S. SCOULERIANA Barratt 1 Shrubs, usually with several to many stems at the base, sometimes to 15 m tall 4 Dwarf, creeping shrubs, 2-8 cm tall; near or above timberline 90 5 Leaves 7 mm or less long, not glaucous beneath; old leaves usually present; capsules not hairy S . ROTUNDIFOLIA Trautv . 5 Leaves mostly over 7 mm long, glaucous or not beneath; old leaves present or not; capsules hairy 6 Leaf tip usually rounded or slightly notched; leaves glaucous and prominently netted-veined beneath S . RETICULATA L . 6 Leaf tip usually pointed; leaves glaucous or not beneath, often strongly pinnately-veined but usually not prominently netted-veined beneath S. ARCTICA Pall. Erect shrubs, mostly over 3 dm tall; only occassionally above timberline 7 Leaves mostly linear, over 6 times longer than wide, usually less than 1 cm wide; twigs never pruinose S . FLUVIATILIS Nutt . 7 Leaves less than 6 times longer than wide, or if more then not linear; twigs sometimes pruinose 8 Leaves densely white-hairy or silvery-hairy beneath, the hairs concealing the leaf surface or nearly so, dark green and not hairy or more sparsely hairy above; capsules hairy S . DRUMMONDIANA Barratt 8 Leaves not densely white-hairy or silvery-hairy beneath, or if so, then similarly hairy above; capsules hairy or not 9 Twigs of previous year pruinose, sometimes only apparent at the nodes, especially behind buds; leaves usually hairy 10 Catkins on leafy peduncles, usually loosely flowered, less than 2 times longer than wide; all buds about the same size and less than 4 mm long; twigs mostly reddish S. GEYERIANA Andress. 10 Catkins usually sessile, densely flowered, more than 2 times longer than wide; mature buds of two sizes, the larger over 4 mm long; twigs often yellowish S . DRUMMONDIANA Barratt 9 Twigs not pruinose (rarely thinly pruinose in Salix phylicifolia) 11 Plant with mature female catkins 12 Mature capsules hairy 91 13 Catkins sessile or nearly so 14 Pedicels less than 1 mm long; styles over 0.7 mm long; leaves, if present, elliptic, entire or shal- lowly toothed; twigs of previous year chestnut to red, shining S. PHYLICIFOLIA L. 14 Pedicels 1-2 mm long; styles less than 0.8 mm long; leaves, if present, obovate to oblanceolate , or if elliptic, then coarsely wavy-toothed; twigs of previous year yellowish to reddish-brown dull S . SCOULERIANA Barratt 13 Catkins on leafy peduncles 15 Capsules on pedicels 2-5 mm long; style less than 0.5 mm long S . BEBBIANA Sarg . 15 Capsules sessile or on pedicels less than 2 mm long; style over 0.5 mm long except in S . scouleriana 16 Leaves glaucous or distinctly lighter beneath, variously hairy 17 Plants mostly over 2 m high, most common at middle elevations in uplant forests or burned- over areas; catkins appearing before the leaves; leaves, if present, obovate to oblanceolate S . SCOULERIANA Barratt 17 Plants mostly less than 2 m high, most common in damp areas at higher elevations; catkins appearing with the leaves; leaves mostly elliptic to ovate 18 Catkins 1-2 cm long; pedicels usually less than 0.5 mm long; petioles mostly 1-3 mm long S . BRACHYCARPA Nutt . 18 Catkins over 2 cm long; pedicels often over 0.5 mm long; petioles mostly over 3 mm long S . GLAUCA L . 16 Leaves nearly the same green above and beneath, silky hairy on both surfaces to almost without hairs 19 Leaves over 3 times longer than wide, mostly less than 3 cm wide; catkins 1-3 cm long S. WOLFII Bebb. 19 Leaves less than 3 times longer than wide, mostly over 2 cm wide; catkins 3-6 cm long S. COMMUTATA Bebb. 12 Mature capsules not hairy 20 Leaves nearly the same green above and beneath 92 21 Leaves entire, not hairy; plants mostly less than 1 m high S . FARRAE Ball 21 Leaves either toothed or hairy; plant height various 22 Larger leaves long-tapering to the tip; glandu- lar processes on the petiole near base of leaf blade S. LASIANDRA Benth. 22 Larger leaves more abruptly tapering to the tip; glandular processes absent S. NOVE-ANGLIAE Andress. 20 Leaves glaucous beneath or at least distinctly lighter beneath than above 23 Leaves mostly entire; plants mostly less than 1 m tall S . FARRAE Ball 23 Leaves mostly toothed; plants mostly taller 24 Larger leaves long-tapering to the tip S. LASIANDRA Benth. 24 Larger leaves more abruptly tapering to the tip 25 Styles less than 0.7 mm long S . RIGIDA Muhl . 25 Styles over 0.7 mm long S. MONTICOLA Bebb. Plant without mature female catkins; with mature leaves 26 Leaves mostly widest above the middle, usually at least sparsely hairy, distinctly lighter beneath than above; twigs often hairy; freshly stripped bark of living twigs of previous year usually with a "skunky" odor; most common in drier locations in upland forests or burned-over areas S. SCOULERIANA Barratt 26 Plant not with the above combination of characters 27 Leaves distinctly lighter beneath than above, usually sparsely hairy, mostly elliptic, often entire; twigs of the year hairy, usually red- purple; mature buds usually with depressed margins; bark of older twigs cracked giving white-streaking appearance; in all willow habitats except high mountains S. BEBBIANA Sarg. 27 Plant not with the above combination of characters 93 28 Leaves lanceolate to elliptic, not hairy or with very few scattered hairs, nearly the same green on both sides, toothed S. LASIANDRA Benth. 28 Leaves not with the above combination of characters 29 Leaves mostly entire, nearly the same green on both sides, densely silky hairy on both sides to almost without hairs; twigs of the year hairy See separation 19 above 29 Leaves not with the above combination of characters; twigs various 30 Most leaves entire or nearly so 31 Leaves conspicuously hairy 32 Leaves usually sparsely to moderately hairy; petioles mostly over 3 mm long S . GLAUCA L . 32 Leaves usually densely hairy, the hairs often concealing the leaf surface; petioles mostly less than 3 mm long S . BRACHYCARPA Nutt . 31 Leaves without hairs or with very few scattered hairs 33 Leaves dark green and shining above S . PHYLICIFOLIA L . 33 Leaves yellowish-green and dull above S . FARRAE Ball 30 Most leaves toothed 34 Leaves not glaucous beneath although some- times slightly lighter; twigs of the year and sometimes twigs of the previous year with long, spreading hairs S. COMMUTATA Bebb. 34 Leaves glaucous beneath; twigs of the year either not hairy or with short hairs appressed to the twigs 35 Larger leaves long-tapering to the tip S . LASIANDRA Benth. 35 Larger leaves more abruptly tapering to the tip 36 Leaf blades at the base mostly rounded or with their sides forming an angle greater than 90 degrees 94 37 Bark of older twigs often silvery or gray; twigs of the year rarely hairy; mostly at middle or lower elevations along streams and ditches; leaves usually lanceolate S . RIGIDA Muhl. 37 Bark of older twigs not silvery or gray; twigs of the year often hairy; mostly at middle or higher elevations along streams and in swamps and wet meadows; leaves usually elliptic to ovate S. MONTICOLA Bebb. 36 Leaf blades at the base mostly with their sides forming an angle less than 90 degrees S. PHYLICIFOLIA L. BETULACEAE Birch Family 1 Main bracts of the usually clustered pistillate catkins hardened, forming a conelike structure persistent on the plant after the shed of the ripened nutlets ALNUS 1 Main bracts of the usually single (paired) pistillate catkins not hardened or forming a conelike structure, but rather deciduous with the ripened nutlets BETULA Alnus Hill Alder 1 Catkins developing and flowering with the leaves; nutlet winged; winter buds acute A. SINNATA (Regel) Rydb . 1 Catkins developing and flowering before the leaves develop; nutlet wingless; winter buds rounded or blunt A . INCANA (L . ) Moench 95 Betula L. Birch 1 Plant shrubs from less than 1 to as much as 3 (6) m tall; fruit narrowly winged, the wings usually not so broad as the nutlet itself; young growth densely puberulent as well as strongly wart-glandular; leaves mostly 1-2 (but rarely up to 4) cm long, simply crenate-serrate or serrate, usually rather leathery; primarily in or near marshes, lakes, bogs and stream margins B. GLANDULOSA Michx. 1 Plants mostly tall shrubs or small trees usually 4 (to 20) m tall; wing of the fruit usually at least as broad as the nutlet itself; young growth more often glabrous or crisp- pubescent than puberulent, sometimes scarcely at all warty; leaves various, often well over 4 cm long, mostly slightly lobed or doubly serrate, usually not leathery; plants of many habitats, not characteristically of swamps B . OCCIDENTALIS Hook . URTICACEAE Nettle Family 1 Plants with alternate, exstipulate, entire leaves and without stinging hairs PARIETARIA PENNSYLVANICA Muhl. 1 Plants with opposite, stipulate, toothed leaves , and stinging hairs URTICA DIOICA L. LORANTHACEAE Mistletoe Family Arceuthobium Bieb. Nom . Conserv . Dwarf Mistletoe 1 Flowers sessile or (the pistillate) with short, slender pedicels up to 1 mm long, usually in pairs at each node; staminate flower buds lenticular, the lateral perianth segments keeled; stems often over 2 mm thick and usually at least 3-4 cm long A. CAMPYLOPODUM Engelm. 1 Flowers terminal on short, lateral, jointed branches, the branches (at least those bearing staminate flowers) often more than 2 per node; staminate flower buds subglobose, neither lenticular nor with keeled lateral perianth segments; stems rarely as much as 2 mm thick, often less than 3 cm long A. AMERICANUM Nutt . 96 POLYGONACEAE Buckwheat Family Leaves without sheathing stipules ERIOGONUM Leaves with evident (often membranous) sheathing stipules 2 Leaf blades reniform; perianth 4-parted nearly to the base; pistil 2-carpellary , the ovary strongly com- pressed OXYRIA DIGYNA (L.) Hill 2 Leaf blades never reniform, if cordate or hastate then the perianth 5 (6)-lobed or -parted, the pistil 3-carpellary 3 Perianth segments usually 7 (rarely 4) , 1 or more often with a grain like callosity on the outside; leaves not jointed to the stipular base RUMEX 3 Perianth segments usually 5 (rarely 4 or 6) , never with grain like callosities; leaves often jointed to the stipular base POLYGONUM Eriogonum Michx. Wild Buckwheat 1 Perianth narrowed to a slender stipelike base which is jointed to (and only slightly if at all thicker than) the pedicel, the stipe (0.5) 1-2 (3) mm long; flowering stems sometimes with a whorl of leaves (bracts) about midlength, the bracts of the inflorescence more or less verticillate 2 Involucres solitary at the tip of the naked flowering stems, with oblong and recurved lobes, ebracteate; perianth pilose-lanate below (very occasional specimens of E. umbellatum, which usually has a glabrous or only slightly pubescent perianth, will key here also) E. CAESPITOSUM Nutt . 2 Involucres either more than 1 per flowering stem or the stem with a whorl of leaves from below midlength to immediately below the involucres 3 Perianth usually pubescent externally 4 Teeth of the (usually campanulate) involucres oblong, mostly (1.5) 3 (5) mm long, spreading to reflexed E . UMBELLATUM Torr . 97 4 Teeth of the (commonly turbinate) involucres tri- angular to lanceolate, erect, usually less than 1.5 mm long; leaves various; plants usually caespitose E. FLAVUM Nutt. 3 Perianth usually glabrous externally, rarely pube'scent (in E. heracleoides) but then the involucres more than 1 and umbellate and the flowering stem with a whorl of leaves near midlength 5 Flowering stems usually with a whorl of foliaceous bracts at about midlength, these sometimes reduced to only 1 or 2 or even wanting; leaves mostly linear or linear-lanceolate to linear-oblanceolate (oblanceo- late) , grayish-lanate on both surfaces or the upper surface only sparsely woolly and much less grayish, the blade at least 3 (usually well over 4) times as long as broad E . HERACLEOIDES Nutt . 5 Flowering stems usually without floral leaves below the umbel, but occasionally with 1 or 2; leaf blades usually oblanceolate to elliptic or oval, rarely as much as 3 times as long as broad E. UMBELLATUM Torr. 1 Perianth rounded to acute at base, narrowed to the point of attachment (joint) with the pedicel but without a slender stipelike base, occasionally narrowed to a more slender base usually less than 0.5 mm long (borderline plants are not included here if the inflores- cence is verticillate-bracteate at base) E . OVALIFOLIUM Nutt . Polygonum L. Doorweed; Knotweed; Smartweed 1 Plants annuals, usually with small taproots and without nodally rooting branches, characteristically in dry areas, but sometimes on wet soil 2 Stems twinning; leaf blades sagittate-ovate P. CONVOLVULUS L. 2 Stems not twinning; leaves never sagittate 3 Pedicels becoming sharply recurved by (or shortly after) anthesis, the older flowers reflexed; plants spreading to erect; racemes elongate, the flowers not at all crowded, borne in the axils of bracts that are much reduced but gradually transitional to the leaves below P . DOUGLASII Greene 98 3 Pedicels erect or spreading but not sharply reflexed; plants sometimes prostrate; flowers often greatly- crowded in short terminal racemes, the bracts some- times much exceeding the flowers 4 Flowers in terminal spikelike racemes, closely crowded and usually overlapping, borne in the axils of often considerably longer bracts; leaves linear to linear-lanceolate or linear-oblanceolate , rarely over 2 mm broad, never with the lateral veins plainly visible; stems usually fairly sharply angled rather than terete and striate 5 Floral bracts mostly plainly white-margined, the upper ones often no longer than the flowers; plants very commonly over 7 cm tall P . CONFERTIFLORUM Nutt . 5 Floral bracts only slightly or not at all white- margined, the upper ones usually exceeding the flowers; plants usually less than 7 cm tall P. KELLOGGII Greene 4 Flowers mainly axillary to the leaves, seldom strongly crowded, the upper ones often borne in the axils of (and longer than) reduced bracts; leaves various, but often elliptic or oblong to obo- vate, commonly over 2 mm broad; stems mostly terete and longitudinally striate 6 Outer 3 perianth segments cucullate-keeled, longer and broader than the inner 2; leaves oval to obovate, rounded (obtuse); achenes usually included, smooth P. ACHOREUM Blake 6 Outer perianth segments generally not cucullate- keeled, usually only slightly (if at all) longer and broader than the inner 2; leaves linear to lanceolate or oblanceolate , often more or less acute; achenes mostly faintly striate, often exserted P. AVICULARE L. Plants perennials, often rhizomatous, generally growing in or near water, the stems tending to root freely wherever they touch the soil 7 Flowers borne in a single, terminal, pedunculate head on a leafless to bracteate or only few-leaved stem; plant from a short, thick rhizome, the leaves chiefly basal 99 8 Racemes mostly less than 1 (to 1.5) cm broad (when pressed), usually well over 3 times as long as broad, the lower flowers, at least, usually replaced by bulblets P. VIVIPARUM L. 8 Racemes mostly at least 1.5 cm broad (when pressed), rarely (if ever) over 3 times as long as broad, with none of the flowers replaced by bulblets P. BISTORTOIDES Pursh 7 Flowers in axillary as well as terminal racemes on foliate stems; plants various P. AMPHIBIUM L. Rumex L. Sorrel 1 Flowers mostly or entirely imperfect, the plants usually dioecious; leaves either sagittate or hastate, or the plant a strong montane to alpine perennial with numerous elliptic to oblanceolate leaves 2 Leaves tapered at each end, never at all sagittate or hastate; plants alpine to subalpine, with thick tap- roots; outer perianth segments not sharply reflexed in fruit R . PAUCIFOLIUS Nutt . 2 Leaves in part (at least) hastate to sagittate; more or less weedy species, often with rhizomes; outer perianth parts sometimes sharply reflexed in fruit R . ACETOSELLA L . 1 Flowers all (or mostly) perfect; leaves varied in shape but never hastate and only rarely sagittate; plants mainly of the lowlands 3 Plant strongly rhizomatous, the leaves usually leathery R. VENOSUS Pursh 3 Plant not rhizomatous, usually with a strong taproot, the leaves various 4 Inner perianth segments becoming more or less strongly toothed or dissected (the teeth at least 1 mm long) , one or more with a prominent callosity R . MARITIMUS L . 4 Inner perianth segments entire to slightly erose or denticulate, but never toothed or dissected (the denticulations less than 1 mm long), sometimes without callosities 5 Valves without callosities, even in fruit R. OCCIDENT ALIS Wats. 100 5 Valves (1, 2, or all 3) with a prominent dorsal callosity 6 Stems unbranched below the inflorescence; petioles usually more or less papillate- or scabrid-puberulent; callosities often reticulate-pitted R . CRISPUS L . 6 Stems with axillary (often much reduced) branches at some or all of the nodes below the inflorescence; petioles rarely scabrid- or papillate-puberulent; callosities not reticulate-pitted R . SALICIFOLIUS Weinm . CHENOPODIACEAE Goosefoot Family 1 Bracts and leaves strongly spinulose at the tips; flowers perfect; fruiting calyx broadly winged transversely SALSOLA KALI L . 1 Bracts and leaves not spinulose, the spines (if any) cauline in origin; fruiting calyx usually not transversely winged but if so the flowers generally in part imperfect 2 Plants spinose-branched shrubs with linear, semi- terete leaves; embryo spirally coiled; endosperm lacking SARCOBATUS VERMICULATUS (Hook . ) Torr . 2 Plants herbs or shrubs, if shrubby and at all spinose then with flattened leaves and with an annular embryo surrounding the endosperm 3 Leaves, at least those present at anthesis, linear to narrowly lanceolate, entire, densely hairy, some- times stellate, and (like the rest of the plant) grayish to rufous; embryo annular, surrounding the endosperm 4 Pubescence largely stellate; plants monoecious, the pistellate flowers enclosed in 2 partially connate bractlets, but without a perianth; seed erect EUROTIA LANATA (Pursh) Mog. 4 Pubescence simple; plants mostly perfect-flowered, all with a 5-merous, ultimately horizontally winged perianth; seed horizontal KOCHIA SCOPARIA (L . ) Schrad. 3 Leaves at anthesis either broader (than narrowly lanceolate) or toothed or not grayish-hairy; embryo sometimes spiral 101 5 Embryo spirally coiled; endosperm scant or lacking; leaves linear and more or less terete; flowers all axillary, borne singly, in clusters of 2-5 along the main stem, or in lateral spikes; perianth in fruit horizontally winged, transversely corrugate, or more or less corniculate SUAEDA DEPRESSA (Pursh)Wats 5 Embryo annular, usually surrounding a copious endo- sperm; flowers (at least in part) generally in crowded, bracteate to ebracteate spikes or panicles; perianth often neither horizontally winged, nor transversely corrugate, nor corniculate, sometimes lacking 6 Perianth (if any) consisting of a single (2 or 3) bractlike segment; smaller than the fruit and not enclosing it; seed vertical; annuals with entire to hastately lobed leaves MONOLEPIS NUTALLIANA (Schultes) Greene 6 Perianth 3- to 5- lobed; fruit at least partially enclosed by the perianth or by large subtending bracts; seeds often horizontal; annuals or perennials, the leaves often toothed 7 Flowers imperfect, the pistillate naked or with greatly reduced perianth but each subtended and enclosed by 2 accrescent, sepaloid bracteoles , the staminate flowers ebracteate and with a 3- to 5-lobed perianth 8 Plants (young herbage and branches) stellate-scurfy with small spreading hairs; bractlets of the pistillate flowers connate and ultimately closely investing the fruit, much compressed from the sides, wing-mar- gined, and nearly orbicular in outline; shrubs with entire, oblanceolate leaves, the branches often spinose at the tip GRAYIA SPINOSA (Hook.) Mog . 8 Plants not stellate-scurfy; bractlets of the pistillate flowers mostly not connate, sometimes dorsiventrally compressed; herbs or shrubs, if shrubby then usually with broader, sometimes toothed leaves ATRIPLEX 7 Flowers mostly perfect and with a regular, (3-4) 5-lobed perianth 9 Plants annual; perianth not winged in fruit CHENOPODIUM 9 Plant perennial; perianth becoming carinate and transversely winged in fruit KOCHIA SCOPARIA (L.) Schrad. 102 Atriplex L. Orache; Greasewood; Saltbush; Silverscale 1 Plants dioecious, perennial shrubs, the main branches woody, more or less rigid, sometimes spinose at the tip 2 Plants woody only at the base, the younger stems herbaceous, rarely over 4 dm tall; fruiting bractlets not prominently winged lengthwise A . GARDINERI (Mog . ) Standi . 2 Plants woody almost throughout, usually over 4 dm tall; fruiting bractlets usually prominently winged lengthwise A. CANESCENS (Pursh) Nutt . 1 Plants monoecious annuals, herbaceous, not at all (or only very slightly) woody at base 3 Leaves opposite below, generally alternate above (except sometimes when immature), usually not grayish-farinose on either surface, often glabrate, when farinose the farina not covering half the surface and the leaves greenish in appearance A . HORTENSIS L . 3 Leaves sometimes alternate throughout, grayish-farinose on both surfaces or at least on the lower, the meal tend- ing to cover the entire surface 4 Fruiting bracts 2-3 mm long, connate to the tip, cun- eate, truncate or somewhat rounded and slightly 2- to 3 (5) -toothed across the tip, usually smooth on the back; leaves sessile to short-petiolate, truncate to subcordate or somewhat hastate at base, entire to undu late, but not toothed A. TRUNCATA (Torr.) Gray 4 Fruiting bracts mostly over 3 mm long, never at once cuneate and with a subtruncate tip, often conspic- uously toothed or tuberculate on the back; leaves more commonly either cuneate at base, or petiolate, or with toothed margins 5 Plants rounded, mostly 2-5 (8) dm tall, native, not weedy; leaves entire to slightly toothed; pistil- late bracts connate to well above the middle, often with a stipelike base, broadest above midlength, with greenish, foliaceous, usually strongly lacin- iate margins and mostly strongly tuberculate- appendaged and greatly hardened sides; radicle superior A . ARGENTEA Nutt . 103 5 Plants erect, usually not rounded, 2-20 dm tall, introduced and usually weedy; leaves plainly dentate; pistillate bracts connate not quite to midlength, broadest at or below the middle, the greenish margin mostly dentate, the sides not greatly hardened and usually with only short tubercles; radicle lateral (i.e. intermediate between superior and inferior A . ROSEA L . Chenopodium L . Lamb's Quarters; Goosefoot; Pigweed 1 Seed usually erect, the fruit laterally flattened; leaves large, triangular, often hastate, greenish on both surfaces; flowers all glomerate in the axils and in a single terminal spike, or in both axillary and terminal, simple to compound spikes; perianth often turning red at maturity 2 Glomerules less than 4 mm broad, aggregated into numerous, axillary, simple to compound spikes; calyx not reddish and fleshy 3 Axillary glomerules simple; stems usually simple and erect C. HIANS Standi. 3 Axillary glomerules compound or if simple then stems low growing and spreading C. RUBRUM L. 2 Glomerules often over 4 mm broad at maturity of the flowers, mostly in a single, terminal spike, but sometimes in a more or less compound spike, the flowers terminal on the main branches; calyx often reddish and fleshy C. CAPITATUM (L.) Asch. 1 Seed mostly horizontal, the fruit flattened at the tip, if seed vertical then the leaves either farinose or not hastate; flowers more diffusely borne, not all in axillary glomerules of axillary and terminal spikes; perianth not reddish at maturity 4 Plant usually prostrate or low and spreading (erect); leaves lanceolate to oblong-ovate, green above, grayish- farinose beneath, sinuate-dentate; at least some of the fruits usually with the seed vertical C . GLAUCUM L . 4 Plant usually erect; leaves various but if grayish-farinose beneath then the seeds all horizontal 104 5 Leaf blades entire to once or twice hastately lobed at base, linear or oblong to triangular-ovate, the margin mostly not toothed; pericarp not tightly adherent to the seed C. FREMONTII Wats. 5 Leaf blades usually toothed on the margin as well as fre- quently hastately lobed, the teeth sometimes inconspicuous pericarp generally very tightly adherent to the seed 6 Leaves linear to narrowly lanceolate, only lightly if at all hastately lobed, usually at least 4 times as long as broad C. LEPTOPHYLLUM (Mog.) Wats. 6 Leaves broadly lanceolate or ovate to triangular, often prominently hastately lobed, usually less than 4 times as long as broad C . ALBUM L . AMARANTHACEAE Amaranth Family Amaranthus 1 Flowers in small axillary clusters, never in terminal elongate spikes; leaf blades rarely over 3 cm long A. ALBUS L. 1 Flowers in terminal and axillary, simple to compound spikes; leaf blades usually well over 3 cm long A . RETROFLEXUS L . PORTULACACEAE Purslane Family 1 Flowers closely clustered in scorpioid umbels or panicles; sepals 2, scarious or scarious-margined; petals 2, 3, or 4, much less evident than the sepals; stigmas 2; stamens 1-3 SPRAGUEA UMBELLATA Torr . 1 Flowers single to many in usually open racemes or cymes; sepals 2-many, usually not scarious; petals mostly 5 or more, generally rather showy; often the stigmas more than 2 and the stamens more than 3 2 Plants annual or perennial, sometimes with slender rootstocks or stolons but never with fleshy corms or thick fleshy taproots; petals usually white (pinkish); sepals 2; stamens 2-5 MONTIA 2 Plants perennial, with fleshy corms or thick fleshy taproots; petals usually pink or red; sepals sometimes more than 2 and stamens often more than 5 105 3 Capsule circumscissile near the base, the lid sometimes splitting upward; sepals sometimes more than 2; petals and stamens often more than 5; stigmas frequently more than 3 LEWISIA 3 Capsule dehiscent downward by 3 valves; sepals 2; petals and stamens usually 5; stigmas 3 CLAYTONIA LANCEOLATA Pursh Lewisia Pursh 1 Plants with a globose or ovoid corm not over 1 cm long; basal leaves lacking (rarely 2) at anthesis; cauline leaves 2-3 (4-5), approximately whorled L . TRIPHYLLA (Wats . ) Robins 1 Plant with a fleshy, often napiform or carrot-shaped root more than 1 cm long; basal leaves present at anthesis; cauline leaves usually reduced and bractlike, mostly alternate 2 Sepals (4) 5-9, imbricate; flowers 1 per scape, the peduncle readily disarticulating above the whorl of linear, scarious bracts that are borne about midlength of the scape L . REDIVIVA Pursh 2 Sepals 2 (sometimes apparently 4 because of 2 immedi- ately subtending bracts); flowers often 2-many, the pedicels not disarticulating; bracts not whorled L . PYGMAEA (Gray) Robins Montia L. Miner's Lettuce 1 Cauline leaves usually several, alternate, with narrow petioles or petiole-like bases that are generally slightly enlarged and scarious at the juncture with the stem; plant perennial or annual, if annual the petals not over 5 mm long and rarely exceeding the sepals M . LINEARIS (Dougl . ) Greene 1 Cauline leaves mostly opposite, frequently sessile, if alternate then the plant an annual and the petals at least twice as long as the sepals M . CHAMISSOI (Ledeb.) Robins & Fern . 106 CARYOPHYLLACEAE Pink Family 1 Calyx polysepalous , the segments distinct nearly or quite to the base 2 Styles nearly always 5; capsule narrowly cylindric, delicately membranous, mostly (1) 2-3 times as long as the calyx and curved near the tip, dehiscent by 10 usually revolute-margined teeth CERASTIUM 2 Styles usually 3 or 4. if 5 then the capsule not cylindric and curved near the tip, but dehiscent by fewer than 10 teeth or valves 3 Styles normally 5 (4) alternate with the sepals; valves of the capsule entire, opposite the sepals SAGINA SAGINOIDES (L.) Britt. 3 Styles usually 3 or if 4 or 5 then opposite the sepals and valves of the capsule alternate with the sepals 4 Petals more or less deeply bilobed, sometimes rudimentary or wanting; capsule dehiscent by twice as many teeth as there are styles; stamens and petals inserted under the ovary STELLARIA 4 Petals usually rounded, rarely somewhat shallowly retuse; capsules often dehiscing by the same num- ber of valves as there are styles, the valves entire or 2-toothed; stamens and petals often inserted at the edge of a distinct disc ARENARIA 1 Calyx gamosepalous , forming a distinct tube that in most cases is longer than the lobes 4 Styles commonly 2, very occasionally 3 5 Petals appendaged at the juncture of the claw and blade SAPONARIA OFFICINALIS L . 5 Petals neither appendaged nor clearly differentiated into claw and blade VACCARIA SEGETALIS (Neck.) Garcke 4 Styles commonly 3 to 5 6 Styles normally 3, occasionally 4 or 5 but then the flowers usually perfect SILENE 6 Styles normally 5, sometimes 4, the flowers then usually imperfect LYCHNIS 107 Arenaria L. Sandwort 1 Leaves narrowly oblong to ovate or obovate, not acerose, mostly well over 2 mm broad; plants perennial; seeds often strophiolate A . LATERIFLORA L . 1 Leaves mostly narrowly linear and acerose, if (as rarely) over 1.5 mm broad then the plants annuals 2 Capsule dehiscing by 3 entire valves; plants mostly low and matted, usually not over 10 (but occasionally up to 15) cm tall, the primary leaves mostly less than 10 mm long, often with secondary leaves fascicled in their axils; flowers usually 10-many in open cymes; seeds plump, 0.5-1.5 mm long A. OBTUSILOBA (Rydb.) Fern. 2 Capsule dehiscing by 6 valves; plants mostly either with flowering stems well over 10 cm tall or the flowers closely aggregated in congested cymes; leaves often over 10 mm long, seldom with secondary leaves fascicled in their axils; seeds flattened and more or less wing- margined, (1.25) 1.5-3 mm long A. CONGESTA Nutt. Cerastium L. Mouse-ear Chickweed 1 Plant a native perennial with petals at least half again as long as the sepals C. ARVENSE L. 1 Plant either an annual, or a weedy biennial or perennial and with petals subequal to the sepals C . VULGATUM L . Lychnis L. 1 Flowers imperfect (the plants dioecious); blades of the petals well over 5 mm long L. ALBA Mill. 1 Flowers mostly perfect; blades of the petals less than 5 mm long L. DRUMMONDII (Hook.) Wats. 108 Silene L. Campion; Catchfly; Wild Pink 1 Plants annuals, more or less weedy, mostly in waste places, but often apparently native 2 Plant glabrous above, often glandular in bands just below the nodes; blade of the petals 2-4 mm long S . ANTIRRHINA L . 2 Plant pubescent throughout, not glandular in bands below the nodes; blade of the petals 7-10 mm long S . NOCTIFLORA L . 1 Plants native perennials, mostly montane or on undisturbed soil 3 Calyx glabrous; plant a pulvinate perennial usually less than 10 cm tall S . ACAULIS L . 3 Calyx pubescent; plants usually over 10 cm tall 4 Corolla, including the carpophore and blades, usually less than 10 (12) mm long; flowers in open leafy cymes S . MENZIESII Hook. 4 Corolla, including the carpophore and blades, usually over 12 mm long; flowers mostly subtended by considereably reduced bracts 5 Appendages 4 or 6; petals equally 4-lobed or the middle lobes again deeply divided S . OREGANA Wats . 5 Appendages usually 2, if 4 then the blades bilobed or unequaly 4-lobed S. PARRYI (Wats.) Hitchc.&Mag. Spergularia (Pers.) J.& C. Presl Nom.Conserv. Sand Spurry 1 Stamens usually 10, rarely as few as 6 or 7 S. RUBRA (L.) J.&C. Presl 1 Stamens 2-5 S. MARINA (L.) GRISEB . Stellaria L. Starwort; Chickweed 1 Leaves, at least the basal, tending to be oblong, ovate, or ovate-lanceolate, some usually more or less petiolate; flowers often single in the axils; petals usually much shorter than the sepals 2 Flowers single in the axils 109 3 Leaves usually glabrous, the margins minutely crisped; sepals scarious-margined, acute S. CRISPA Cham. & Schlecht. 3 Leaves always ciliate at base, the margins not at all crisped; sepals slightly if at all scarious-margined, more or less obtuse S. OBTUSA Engelm. 2 Flowers in axillary or terminal cymes S . CALYCANTHA (Ledeb . ) Bong Leaves linear to lanceolate, all usually sessile; flowers mostly in cymes or umbels, rarely single; petals often exceeding the sepals 4 Petals rudimentary or absent, less than half the length of the 2-3 mm sepals; stems and pedicels very slender; flowers more or less numerous in scarious-bracteate, umbellate cymes S. UMBELLATA Turcz. 4 Petals usually well over half as long as the sepals which are often over 3 mm long; stems and pedicels stouter; flowers single to many and cymose, the cymes sometimes leafy-bracteate 5 Flowers axillary, not cymose; petals at least as long as the sepals 6 Leaves mostly linear or linear-lanceolate, stiff, sharply acute; sepals about 4 mm long at anthesis S . LONGIPES Goldie 6 Leaves from linear-lanceolate to oblong, acutish to obtuse, not stiff; sepals often less than 4 mm long at anthesis S . CRASSIFOLIA Ehrb . 5 Flowers few to many in cymes; petals often shorter than the sepals 7 Cymes leafy-bracteate; petals shorter than the sepals, sometimes wanting S . CALYCANTHA (Ledeb . ) Bong 7 Cymes either membranous-bracteate or the petals longer than the sepals 8 Leaf margins very finely tuberculate-scaberulous as viewed under a strong (30-power) lens S . LONGIFOLIA Muhl . 8 Leaf margins smooth S. LONGIPES Goldie 1 10 RANUNCULACEAE Buttercup Family Flowers very irregular, bilaterally symmetrical, showy 2 Upper sepal spurred but not hooded; petals 4, not concealed by the sepals DELPHINIUM 2 Upper sepal hooded but not spurred; petals usually 2, concealed inside the hood ACONITUM COLUMBIANUM Nutt. Flowers essentially regular, often inconspicuous 3 Petals prominently spurred, showy; fruit of several follicles; plant perennial AQUILEGIA 3 Petals not at once prominently spurred and showy (often lacking), if spurred (as in Myosurus) then incon- spicuous, the fruit other than follicular, and the plant an annual 4 Plant a scapose, linear-leaved annual; flowers incon- spicuous; sepals spurred; fruit achenial, the achenes numerous in a slender spicate cluster on a much elongate receptacle MYOSURUS 4 Plant usually perennial; flowers generally showy; fruit often follicular or baccate, when achenial the achenes not borne in a spicate cluster 5 Pistil 1; fruit a berry; leaves large, several times dissected ACTAEA RUBRA (Ait.) Willd . 5 Pistils usually 2 or more; fruit an achene or a follicle; leaves various 6 Fruit a 1-seeded achene 7 Perianth consisting of both the calyx and corolla, the corolla more showy than the calyx RANUNCULUS 7 Perianth either consisting only of the calyx, or the corolla present but less showy than the calyx 8 Sepals inconspicuous, usually greenish (white) , less showy than the stamens; cauline leaves (if any) alternate 9 Leaves simple, palmately lobed; flowers perfect TRAUTVETTERIA 9 Leaves ternately decompound; flowers often imperfect THALICTRUM I I I 8 Sepals usually conspicuous and more showy than the stamens; cauline leaves opposite or whorled 10 Cauline leaves opposite; plants sometimes woody and viny; achenes with a long plumose style; sepals usually 4 CLEMATIS 10 Cauline leaves usually in a whorl of 3; plants never woody or viny; styles short and glabrous to long and plumose; sepals mostly 5 or more ANEMONE 6 Fruit a 2- to many-seeded follicle 11 Leaves simple, the margins merely crenate or dentate CALTHA LEPTOSEPALA DC . 11 Leaves deeply 5-lobed to nearly compound TROLLIUS LAXUS Salisb . Anemone L. Wind Flower 1 Styles plumose 2-3.5 cm long at maturity; flowers very showy, the sepals 2-4 cm long; (A. patens) A. NUTALLIANA DC. 1 Styles much less than 1.5 cm long usually not plumose at maturity; the sepals less than 2 cm long A. MULTIFIDA Poir . Aquilegia L. Columbine 1 Sepals blue or purple to white A. COERULEA James 1 Sepals yellow to pinkish or red A. FLAVESCENS Wats. Clematis L. Virgin's Bower; Vase Flower 1 Sepals bluish to reddish or brownish-purple; flowers single, terminal and pedunculate on the main or on axillary stems 2 Plants herbaceous perennials, not at all viny; flowers solitary at the tips of the main stems; sepals leathery, connivent at base; leaves pinnately dissected C. HIRSUTISSIMA Pursh 112 2 Plants somewhat woody vines; flowers terminal on short axillary stems; sepals neither leathery nor connivent at base; leaves ternate or ternately dissected C . COLUMBIANA (Nutt . ) T . & G . 1 Sepals white or yellowish; flowers paniculate C. LIGUSTICIFOLIA Nutt. Delphinium L. Larkspur 1 Stems notably fistulose, (6) 10-30 dm tall; roots extensive and tough and fibrous, rather than fleshy; leaves with 5-7 main lobes that are variously toothed but not dissected; flowers not particularly showy the sepals rarely over 12 mm long, cupped forward rather than flared; plants of wet habitats, usually in mt . meadows or along streams; the following three species are very closely related and are separable only rather arbitrarily 2 Follicles usually hairy all over (rather glabrous); racemes compact, many-flowered, the pedicels often no longer than the calyx spurs; flowers often whitish- streaked or pale blue D . OCCIDENTALE Wads. 2 Follicles usually either glabrous or pubescent only along the sutures; racemes more or less open, the pedicels generally longer than the spurs; calyx deep purplish 3 Follicles glabrous on the sutures; basal and lower cauline leaves divided 2/3-3/4 (4/5) of their length into (usually) 5 lobes, the larger blades up to 15-20 cm broad D. GLAUCUM Wads. 3 Follicles hairy along the sutures; basal and lower cauline leaves divided almost full length (over 4/5 of the length) into (usually ) 7 main segments, the larger blades seldom over 12 cm broad D. BROWNII Rydb. 1 Stems either not fistulose or the plant otherwise not as above; several of the following species approach D. occidentale, but each can be separated either because of the larger, more showy, flared sepals or because of the habitat, many occurring on dry, open, sagebrush slopes 113 4 Plants usually tall and often somewhat fistulose-stemmed , primarily of wet habitats (the area often drying by mid- season); root system extensive; branched and fibrous (woody) rather than tuberous D . BURKEI Greene 4 Plants of varied habit, usually occurring in dry habitats, such as on sagebrush slopes or in open forests, if (as occasionally) in wet areas, then the root system very small, and fleshy or tuberous rather than tough and fibrous 5 Leaves strongly dimorphic, those of midstem closely overlapping and much shorter-petiolate and more finely divided and more closely spaced than the lower ones; plants with small clusters of somewhat fleshy roots, finely crisp -puberulent D. BURKEI Greene 5 Leaves not noticeably dimorphic, usually rather uniformly spaced and not overlapping; plants various 6 Stems 1-several and often over 4 dm tall, from an extensive root system, mostly glabrous, at least below the inflorescence, usually not glandular pubes- cent; lower petals blue; sepals various, often cupped forward rather than widely flared D. GLAUCESCENS Rydb . 6 Stems mostly single (or occasionally several) , rarely over 4 dm tall, often pubescent with either straight or glandular hairs, if glabrous then the lower petals white or the racemes broad (because of the spreading pedicels), or the sepals unequal and usually rather broad (oblong to somewhat ovate) , always widely flared than cupped forward 7 Lower petals deep blue, shallowly notched, the sinus rarely over 1/5 the length of the blade; sepals unequal, the lowest pair much the longest D . BICOLOR Nutt . 7 Lower petals variously colored, often white or pale blue, but very heavily pencilled, deeply notched, the sinus usually 1/4-1/2 the length of the blade; sepals more nearly equal D . NUTTALLIANUM Pritz . I 14 Myosurus L. Mouse-tail 1 Beak of the achenes well developed , (0.5) 0.8-1.5 mm long; mature spike mostly 5-10 mm long, with 20-50 (90) achenes; sepals various, usually 1-nerved M. ARISTATUS Barth. 1 Beak of the achenes inconspicuous, seldom over 0.5 (0.7) mm long; spike mostly (8) 15-25 mm long at maturity, and often with over 100 achenes; sepals 3 (5) nerved M. MINIMUS L. Ranunculus L. Buttercup; Crowfoot 1 Leaves entire to serrate but none dissected or compound, sometimes lobed at the tip and then the stems stolonous; scale of the nectary forming a distinct pocket, the margins adnate the full length or free for as much as half their length; achenes glabrous (very sparsely pubescent) , the custer usually less than 1 cm broad 2 Achenes 50-200 in a columnar head, longitudinally ribbed R. CYMBALARIA Pursh 2 Achenes less than 50 or in a more or less globular head, not longitudinally ribbed 3 Stems decumbent to prostrate, rooting at the nodes, frequently appressed-pubescent; sepals usually hairy; nectary scale generally considerably broader than long R . FLAMMULA L . 3 Stems erect, not rooting at the nodes, usually glabrous or sometimes the petioles and pedicels pubescent; nectary scale at least as long as broad R . ALISMAEFOLIUS Geyer 1 Leaves (at least in part) deeply lobed to compound, if simple the achenes usually finely puberulent or the cluster of achenes about 1 cm broad; nectary scale various; achenes sometimes hairy or spiny 4 Achenes prominently cross-corrugated; petals white or with a white blade and yellowish claw; nectary scale very short to almost obsolete, broader than long, forming a minute pocket or a mere thickening; plants aquatic R. AQUATILIS L. I 15 Achenes not prominently cross-corrugated; petals usually yellow; plants mostly terrestrial; nectary scale generally rather prominent, often with free margins 5 Plants aquatic or semi-aquatic, often with some finely dissected submerged leaves, the stems usually creep- ing and often nodally rooting; nectary scale conspicuous, more or less adnate to the petal, the margins and tip generally free, bearing the gland on the exposed (ventral) surface rather than concealed beneath it; achenes glabrous, either beakless or with a beak much less than 0.5 mm long, or with corky thickening on the margins 6 Plant annual, erect, not nodally rooting, mostly over 15 cm tall; stylar beak almost lacking, somewhat corky, not over 0.2 mm long; nectary scale usually with a free margin surrounding the gland R. SCELERATUS L. 6 Plant perennial, usually with floating or reclining and nodally rooting stems and less than 15 cm tall; stylar beak commonly well over 0.2 mm long; nectary scale often completely fused with the petal and without free margins above 7 Leaves 5-15 mm long, never finely dissected, merely 3- or 5-lobed, the lobes entire or shallowly notched; stylar beak less than 0.3 mm long; nectary scale free only at the base and along the sides R. NATANS C.A.Meyer 7 Leaves either well over 15 mm long or rather finely dissected; stylar beak mostly over 0.3 mm long; nectary scale usually with a free border all around the gland (R. purshii) R. GMELINII DC. 5 Plants not aquatic and with dissected leaves, the stems mostly not nodally rooting; achenes either hairy or with a conspicuous beak but not corky-thickened on the margin 8 Achenes only moderately compressed (the thickness at least 1/3 the dorsiventral width), often finely pubescent; nectary scale usually short, its margins adnate to the petal nearly or quite to the tip, forming a small pocket; receptacle usually elongating markedly in fruit and sometimes becoming as much as 10 times as long as at anthesis I 16 Achenes in a semiglobular cluster (7) 10-30 mm broad; petals (6) 8-15 mm long, the nectary scale (1) 1.5-3 mm long, more or less oblong, adnate nearly or quite to the tip, the upper margin often ciliate; plant glabrous to sparsely hirsute above, but long-hirsute on the basal stipules and more or less tomentose toward the tips of the main roots; stems mostly ascending to somewhat decumbent, seldom over 15 cm tall R. GLABERRIMUS Hook. Achenes usually in a more elongate or much narrower cluster; petals often less than 6 mm long, the nectary scale usually less than 1 (rarely 1.5) mm long, often broader than long, its upper margin not ciliate; plants often pilose, the roots not tomentose; stems mostly erect and often well over 15 cm tall 10 Achenes finely pubescent (sometimes glabrate) 11 Roots enlarged and clavate, abruptly rounded, tuberlike, 1-2.5 (3) cm long, 2-5 mm thick; stems rarely up to 10 cm tall; basal leaves (if any) deeply divided into 3-5 oblanceolate lobes R. JOVIS A.Nels. 11 Roots not modified as above but tapered gradually to the tip; stems mostly over 10 cm long 12 Petals (if any) 2-6 (8) mm long; basal leaf blades cunneate, at least some of them usually no more than crenate R . INAMOENUS Greene 12 Petals either over 8 mm long or the basal leaves deeply lobed or divided, often cordate R. ESCHSCHOLTZII Schlecht. 10 Achenes glabrous 13 Petals mostly over 8 mm long, if shorter (5-8 mm) then the basal leaves all lobed at least half their length; plants mostly 5-20 cm tall R. ESCHSCHOLTZII Schlecht. 13 Petals usually not over 5 mm long but if longer (to 8 mm) then the basal leaves (at least in part) merely deeply crenate or the stems well over 2 dm tall 14 Beak of the achene 0.1-0.2 mm long; achenes 20-45 per flower R . ABORTIVUS L . 14 Beak of the achene 0.7-0.9 mm long; achenes 50-100 per flower R. INAMOENUS Greene 117 8 Achenes strongly compressed, often discoid (the thick- ness less than the dorsiventral width) , never pubescent; nectary scale elongate, the margins free for at least the upper 1/2 to 2/3 (3/4) of their length; receptacle in fruit not over 2-3 times the length at anthesis 15 Beak of the achenes straight, 2.5-4 mm long; basal leaves apparently pinnately 5- to 7-lobed; petals usually more than 10 mm long R. ORTHORHYNCHUS Hook. 15 Beak of the achenes often recurved or hooked, seldom over 2.5 mm long; basal leaves seldom pinnately lobed; petals sometimes less than 10 mm long 16 Petals considerably longer than the sepals, usually well over 7 (5-18) mm long; basal leaves simple or if compound and with stalked leaflets then the stems either nodally rooting or enlarged and bulbose or cormose at the base R . OCCIDENT ALIS Nutt . 16 Petals mostly over slightly if at all longer than the sepals, usually much less than 7 mm long (if plant borderline in this respect, then the basal leaves compound but the stems neither nodally rooting nor enlarged and bulbose or cormose at base) 17 Basal leaf blades (in part at least) compound, the leaflets usually stalked; receptacle elongating in fruit to at least 3 times its length in flower R . MACOUNII Britt . 17 Basal leaf blades simple, the lobation not extending full length R. UNCINATUS D.Don Thalictrum L. Meadow Rue 1 Flowers perfect, racemose or paniculate; plants either subscapose or with anthers not over 1 mm long T. SPARSIFLORUM Turcz. 1 Flowers usually at least in part imperfect, borne in panicles; plants mostly dioecious, with leafy stems; anthers never less than 1 mm long 2 Achenes spreading to reflexed, elliptic-fusiform in outline, (4) 5-8 (10) mm long, usually less than half as broad, membranous-walled, moderately flattened; stigma commonly purplish, with the style usually 3-4.5 mm long; pistillate inflorescence open, rather leafy, the pedicels slender, of approximately the same length and longer than the achenes; leaflets not prom- inently veined, 1.5-3 cm long T. OCCIDENTALE Gray I 18 2 Achenes often erect or ascending, 3-6 mm long, either subterete and narrowly elliptic in outline, or obliquely obovate-elliptic in outline and strongly compressed; stigma rarely purplish, with the style 1.5-3.5 mm long; pistillate inflorescence often congested, inconspicuously bracteate, some of the pedicels often shorter than the achenes; leaflets mostly 1-2 cm long, often prominently veined T. VENULOSUM Trel . FUMARIACEAE Fumitory Family 1 Outer pair of petals similar, both spurred or saccate at the base; plants scapose DICENTRA UNIFLORA Kell . 1 Outer pair of petals dissimilar, only 1 of them spurred or saccate; plants leafy-stemmed CORYDALIS AUREA Willd. CRUCIFERAE Mustard Family 1 Fruit stipitate, the stipe at least 1 mm long THELYPODIUM 1 Fruit sessile or the stipe less than 1 mm long 2 Pod composed of 2 distinct segments, the basal portion usually valvular, although often indehiscent, usually seed-bearing, sometimes sterile, the upper segment often not valvular, sometimes fertile but more commonly sterile, sometimes consisting entirely of the scarcely narrowed, often flattened or otherwise beaklike style BRASSICA 2 Pod composed of only one segment, this seed-bearing; style often conspicuous but smaller in diameter than the valves and mostly not beaklike 3 Fruit a silicle, varying from cordate to oval, some- what oblong, elliptic, or obcordate, sometimes didymous or only 1-seeded 4 Silicles from greatly compressed to somewhat inflated, but never globose or terete in section, and not didymous 5 Seeds 1 per locule 6 Plant a densely stellate perennial with sessile, appressed, many-rayed hairs; flowers yellow LESQUERELLA ALPINA (Nutt . ) Wats . I 19 6 Plant various, but (except sometimes in Alyssum , an annual) not with sessile, many-rayed stellae; flowers often not yellow 7 Plant scapose; pubescence not stellate or malpig- hiaceous DRABA 7 Plant not scapose; pubescence stellate or malpig- hiaceous ALYSSUM ALYSSOIDES L . 5 Seeds 2 or more per locule 8 Plant a scapose, white-flowered perennial 1-3 cm tall; silicles ovoid, leathery DRABA 8 Plant not scapose, or over 3 cm tall, or with other than an ovoid, leathery silicle 9 Silicles oblong to elliptic, usually over twice as long as broad DRABA 9 Silicles oval to obovate, not over twice so long as broad 10 Petals yellow; plants perennial, densely stellate with appressed hairs LESQUERELLA ALPINA (Nutt.)Wats 10 Petals usually white, if yellow or purplish then plants either annual or not appressed-stellate 11 Style not over 2 mm long; silicles oval in outline, less than 5 mm long; petals not bilobed ALYSSUM ALYSSOIDES L. 11 Style mostly 3-4 mm long; silicles oval- elliptic to obovate, usually at least 5 mm long; petals sometimes bilobed CAMELINA 4 Silicles from conspicuously to only slightly obcompressed , or so greatly inflated as to be terete and often didymous 12 Plant aquatic, scapose, the leaves linear, more or less terete, acicular SUBULARIA AQUATICA L. 12 Plant not aquatic or if apparently so then not scapose and leaves not acicular 13 Fruits inflated, sometimes didymous 14 Petals yellow (rarely purplish); seeds usually more than 1 per locule 15 Pubescence stellate; plants usually of dry areas 16 Silicles 7-20 mm long, often didymous, or at least with a distinct apical sinus 2-4 mm deep, often cordate at base PHYSARIA 120 16 Silicles not didymous, usually without an apical sinus, less commonly with a sinus as much as 1 mm deep, but the silicles then not over 7 mm long, never cordate-based LESQUERELLA ALPINA (Nutt.) Wats. 15 Pubescence, if any, unbranched; plants usually of wet places RORIPPA 14 Petals white or purple; pubescence never sessile- stellate; seeds 1 per locule CARDARIA PUBESCENS (Meyer) Jarm . 13 Fruit more or less obcompressed , rather than inflated 17 Silicles obcordate to triangular, with more than 1 seed per locule; cauline leaves auriculate CAPSELLA BURSA-PASTORIS (L . ) 17 Silicles not obcordate or triangular, or seeds only 1 per locule, or cauline leaves not auriculate 18 Plant stellate-pubescent PHYSARIA 18 Plant glabrous to pubescent with simple (never stellate) hairs 19 Seeds 1 per locule LEPIDIUM 19 Seeds 2-several per locule THLASPI Fruit an elliptic to linear silique, normally (i.e. in normal specimens) more than 1-seeded 20 Petals yellow (sometimes very pale) to orange 21 Plant conspicuously pubescent with 2-rayed (mal- pighiaceous) or occasionally 3- or 4-rayed, sessile, appressed hairs oriented with the axis of the leaf or stem ERYSIMUM 21 Plant glabrous to variously pubescent, but not with predominantly malpighiaceous or 3- or 4-rayed sessile hairs 22 Style (or what appears to be the style) beak- like, nearly as broad as the valves BARBAREA ORTHOCERAS Ledeb . 22 Style not beaklike, if prominent then much narrower than the valves 23 Seeds biseriate 24 Pubescence unbranched or lacking 12! 25 Leaves simple; plants often scapose; siliques strongly compressed DRABA 25 Leaves often pinnate; plants never scapose; siliques terete to slightly compressed RORIPPA 24 Pubescence branched to stellate 26 Plant a scapose perennial with simple, entire leaves DRABA 26 Plant annual or biennial; leaves 1-3 times pinnatifid DESCURAINIA 23 Seeds uniseriate 27 Plant stellate-pubescent; leaves 1-3 times pinnatifid DESCURAINIA 27 Plant with simple pubescence; leaves simple to pinnatifid 28 Style at least 0. 3 mm long 29 Cauline leaves auriculate or cordate- clasping BARBAREA ORTHOCERAS Ledeb . 29 Cauline leaves not auriculate or cordate- clasping RORIPPA 28 Style less than 0.3 mm long SISYMBRIUM Petals white or pinkish to purple, never yellow 30 Seeds biseriate 31 Plant a scapose perennial; siliques compressed DRABA 31 Plant leafy-stemmed; siliques various RORIPPA 32 Siliques much elongate, usually at least 8 times as long as broad ARAB IS 32 Siliques rather short, less than 8 times as long as broad DRABA 30 Seeds uniseriate 33 Pubescence simple (not branched) or lacking 34 Cauline leaves (at least some of them) pinnate or pinnatifid CARD AMINE 34 Cauline leaves entire to toothed 35 Anthers tending to coil after dehiscence THELYPODIUM 35 Anthers not coiling after dehiscence 122 36 Leaves (in part at least) compound CARDAMINE 36 Leaves simple or occasionally lyrate-pinnatifid 37 Plant either with rhizomes or tubers or entirely glabrous and only 2-10 cm tall; style 1-2 mm long CARDAMINE 37 Plant never rhizomatous or tuberous, usually somewhat hairy, mostly over 10 cm tall; style various ARABIS 33 Pubescence branched to stellate 38 Leaves, including those that are cauline, pinnatifid 39 Petals white; style usually at least 0. 5 mm long; plants alpine or subalpine SMELOWSKIA CALYCINA (Steph.) C. A. Mey. 39 Petals usually cream, if white the style less than 0. 5 mm long or plants neither alpine nor sub- alpine DESCURANINIA 38 Leaves, at least those that are cauline, mostly simple 40 Siliques usually with a short stipe at least 0.5- 1 mm long THELYPODIUM 40 Siliques sessile or with a stipe less than 0.5 mm long 41 Plants biennials, glabrous and glaucous THELYPODIUM 41 Plants either annuals or perennials, or if biennials then not glabrous and glaucous ARABIS 123 Arabis L. Rock Cress 1 Seeds wingless or (as in A, hirsuta) with a wing barely as much as 0 . 3 mm broad; siliques erect, often tightly appressed, not over 2 mm broad; flowers usually white but sometimes slightly pinkish- to lavender-tinged 2 Cauline leaves usually auriculate; plants mostly well over 3 dm tall, strongly hirsute at base 3 Seeds uniseriate, the siliques noticeably compressed; outer sepals gibbous-based A. HIRSUTA (L.) Scop. 3 Seeds biseriate, the siliques only slightly compressed; outer sepals not gibbous-based A. GLABRA (L . ) Bernh. 2 Cauline leaves not auriculate; plants usually less than 3 dm tall, often not at all or only sparsely hirsute at base A. NUTTALLII Robins 1 Seeds winged, the wing often over 0.3 mm broad; siliques erect to reflexed, frequently over 2 mm broad; flowers white to pink or purple 4 Basal leaves oblanceolate to oblanceolate-obovate, rounded or only slightly acutish, usually pannose with tiny, grayish, dendritic hairs; plants 0.5-2 dm tall, arising from a multicipital caudex; racemes 3- to 10- flowered, secund in flower; pedicels 2-6 mm long; siliques ascending to spreading or slightly reflexed A. LEMMONI Wats. 4 Basal leaves either not pannose, or (if pannose) then distinctly acute or narrow or plants well over 2 dm tall or in other ways not as above 5 Plants mostly under 2 (3 or occasionally to 7) dm tall (if over 2 dm tall the stems notably slender); perennial with (usually) a multicipital caudex; basal leaves elliptic-oblanceolate to narrowly oblanceolate, 1.5-3 cm long, 1.5-4 (5) mm broad, acute; siliques ascending-erect to arcuate-spreading but not reflexed; seeds uniseriate; plants usually either with markedly glabrous and fleshy leaves or with many very slender stems scarcely 1 mm thick 6 Stems barely 1 mm thick at midlength; basal leaves usually toothed, glabrous or (more commonly) copiously pubescent and somewhat grayish with several-branched hairs 7 Siliques ascending to slightly spreading, 4-5.5 cm long; petals 3 to 4 mm long A. MICROPHYLLA Nutt. 7 Silques divergent to occasionaly reflexed 1 to 2.5 cm long; petals 4.5 to 5.5 mm long; known only from Undine Falls area A. FRUCTICOSA A. Nels. 6 Stems usually well over 1 mm thick at midlength; basal leaves all entire, greenish or fleshy, mostly glabrous but sometimes finely hairy A. LYALLII Wats. 5 Plants mostly well over 3 dm tall, but if shorter then usually with a simple crown, or with reflexed siliques, or in other ways not as above 8 Leaves, except sometimes the upper ones, densely pubescent and often grayish with small dendritic hairs never ciliate with simple or forked hairs; siliques spreading-arcuate to pendulous, but the pedicel curved rather than abruptly reflexed; cauline leaves auriculate A. LIGNIFERA A. Nels. 8 Leaves greenish to grayish, the hairs usually bi- or trifurcate to stellate rather than dendritic , but if dendritic then either the leaves with long, simple or forked cilia, or the siliques sharply reflexed, or the cauline leaves not auriculate 9 Seeds biseriate, the wing nearly 1 mm broad at the widest point; siliques strictly erect, 2-3 mm broad; pubescence (if any) of the lower stem simple to bifurcate, often appressed; basal leaves mostly malpighiaceous -pubescent A. DRUMMONDII Gray 9 Seeds uniseriate (partially uniseriate in A. divaricarpa) , the wing not over 0. 5 mm broad; siliques erect to reflexed, 1-2.5 mm broad; pubes- cence of the lower stem often stellate to dendritic; basal leaves mostly with trifurcate to stellate or dendritic hairs .10 Pubescence of the lower stems and leaves pre- dominantly trifurcate; siliques mostly straight, from rather stiffly erect to spreading A . DIVARICARPA A. Nels. 10 Pubescence more freely branched; siliques mostly either distinctly arcuate or conspiuously reflexed 11 Siliques ascending to spreading-drooping , 4-12 cm long, usually strongly arcuate; pedicels not geniculate and abruptly reflexed at the base A . SPARSIFLORA Nutt . 125 11 Siliques pendulous, 3-7 cm long, nearly or quite straight; pedicels usually geniculate and abruptly reflexed at the base, if gradually curved downward then the cauline leaves not auriculate A. HOLBOELLII Hornem . Brassica L. Mustard 1 Beak conspicuously flattened, 3-nerved; valves 3-nerved B. KABER (DC.) Wheeler 1 Beak more or less terete, usually 1-nerved; valves 1-nerved B . CAMPESTRIS L . Camelina Crantz False Flax 1 Stems strongly hirsute-stellate, at least below; silicles mostly 5-7 mm long; pedicels seldom over 15 mm long C . MICROCARPA Andrez . 1 Stems sparsely hairy to glabrous at the base; silicles 7-9 mm long, usually about 2/3 as broad; pedicels often over 15 mm long C. SATIVA (L . ) Crantz Cardamine L. Bitter Cress 1 Leaves simple C. CORDIFOLIA Gray 1 Leaves compound, at least in part 2 Plants perennial with well-developed (although sometimes short and thickened) rhizomes; petals 3-7 mm long C . BREWERI Wats. 2 Plants annual or biennial (short-lived perennial?) from a taproot, not rhizomatous; petals 2-4 mm long C. OLIGOSPERMA Nutt. Descurainia Webb & Berth. Nom . Conserv. Tansy Mustard 1 Leaves, at least the lower ones, bi- or tripinnate; siliques narrowly linear, mostly over 20-seeded; seeds uniseriate; replum of the silique 2- to 3-nerved D. SOPHIA (L.) Webb 126 1 Leaves mostly pinnate or the siliques clavate or the seeds either less than 20 or partially biseriate; replum of the silique nerveless or 1-nerved 2 Siliques somewhat clavate, rounded above, only slightly or not at all torulose; replum usually not nerved D. PINNATA (Walt.) Britt . 2 Siliques linear or at least not clavate, pointed above, strongly torulose; replum 1-nerved D . RICHARDSONII (Sweet) Schulz Draba L . 1 Plant an annual 2 Upper portion of the stem and (usually) the pedicels pubescent D. PRAEALTA Greene 2 Upper portion of the stem and the pedicels glabrous 3 Leaves usually all basal and rosulate, but rarely 1 or 2 of them cauline, their upper surfaces usually glabrous D. CRASSIFOLIA R. Grah. 3 Leaves usually not all basal and rosulate, but several of them cauline, their upper surfaces often pubescent 4 Pedicels 1-5 (usually at least 1.5) times as long as the elliptic or elliptic-oblong to oblong-oblanc- eolate fruits; silicles 2-3 mm broad D. NEMOROSA L. 4 Pedicels rarely as much as 1 . 5 times as long as the narrowly oblong fruits; silicles 1.5-2.3 mm broad D. STENOLOBA Ledeb. 1 Plant a biennial or perennial 5 Plant a low, scapose, white-flowered perennial mostly 2-6 cm tall; leaves oblanceolate, 5-10 mm long, 1-2 mm broad, very strongly ciliate with simple hairs and often also pubescent with 1- or 2-forked hairs, the midnerve very prominent; silicles oblong-ovate, 3-6 mm long, 1.5-2 mm broad, apiculate, the style 0.1-0.2 mm long, 10- to 20-seeded D . FLADNIZENSIS Wulfen 5 Plant various, but not at once as above if, as some- times, white-flowered 6 Stems leafy, the plant usually not caespitose nor matted 127 7 Style very short or lacking, generally less than 0.2 mm long 8 Leaves densely pubescent on both surfaces with simple and forked to stellate hairs; petals white or cream D . PRAEALTA Greene 8 Leaves generally sparsely pubescent, the upper surface often glabrous; petals mostly yellow 9 Pedicels mostly shorter than the silicles which are narrowly elliptic or narrowly lanceolate- elliptic, 5-12 mm long, and 2-3 mm broad; cauline leaves only 1 or 2 D. CRASSIFOLIA R. Grah. 9 Pedicels mostly equalling or exceeding the silicles which are linear to narrowly oblong, 8-22 mm long and 1.5-2.3 mm broad; cauline leaves usually several D. STENOLOBA Ledeb . 7 Style present, generally conspicuous, at least 0.2 mm long D. AUREA Vahl . Stems mostly leafless; plants usually caespitose and matted 10 Style lacking (rarely 0.15 mm long); plant a short- lived perennial, not matted D. CRASSIFOLIA R. Grah. 10 Style usually well over 0.15 mm long; plants commonly matted and caespitose 11 Pubescence of the leaves (especially that of the lower surfaces) wholly or in large part of sessile or short-stalked, 2-rayed, doubly pectinate hairs, many of which lie parallel to the leaf axis 12 Leaves averaging less than 1.5 mm broad; pubescence of the leaves closely appressed D. OLIGOSPERMA Hook. 12 Leaves averaging about 2 mm broad; pubes- cence of the leaves not closely appressed D. INCERTA Pays. 11 Pubescence of the leaves simple to stellate, never doubly pectinate 13 Leaves almost glabrous except for prominent, straight, simple cilia, although the lower surfaces sometimes sparsely pubescent with forked to stellate hairs D. DENSIFOLIA Nutt . 128 13 Leaves pubescent (often cinereous) on both surfaces 14 Leaves 0.75-1.5 mm broad, conspicuously ciliate with long, simple and bifurcate hairs, the midnerve prominent beneath, the lower surfaces with elongate, tangled, branched hairs, the upper surfaces with simple and forked hairs D. PAYSONII Macbr. 14 Leaves usually at least 2 mm broad, pubescent with cruciate to stellate hairs, the midnerve not prominent D . VENTOSA Gray Erysimum L. Wallflower 1 Petals usually less than 10 (3.5-11) mm long; style rarely more than 1.5 mm long 2 Siliques 1.5-3 cm long; petals 3.5-5 mm long; plant an annual E . CHEIRANTHOIDES L . 2 Siliques mostly 2.5-5 cm long; petals 7-11 mm long; plant a biennial to short-lived perennial E. INCONSPICUUM (Wats.)MacM 1 Petals more than 11 mm long, or style more than 1.5 mm long E. ASPERUM (Nutt.) DC. Lepidium L. Pepper Grass 1 Cauline leaves auriculate to pseudo perfoliate, ovate L. PERFOLIATUM L. 1 Cauline leaves neither auriculate or pseudo perfoliate 2 Silicles oblong-obovate , widest above the middle; petals generally lacking or vestigial; cotyledons incumbent or very slightly oblique L. DENSIFLORUM Schrad. 2 Silicles elliptic to oval, widest near the middle or below; petals sometimes conspicuous or cotyledons oblique to accumbent 3 Silicles approximately elliptic, distinctly longer than broad; cotyledons incumbent; petals lacking or vestigial L . RAMOSISSIMUM A.Nels. 3 Silicles elliptic-rotund to nearly orbicular, nearly or quite as broad as long; cotyledons accumbent to oblique (ours); petals usually rather conspicuous, 1-3 mm long L . VIRGINICUM L. 129 Physaria (Nutt . ) Gray 1 Styles 7-9 mm long; replum obovate to broadly oblong, not constricted; siliques coarsely pubescent with spreading dendritic hairs; ovules 4 on each side of the replum P . DIDYMOCARPA (Pays . ) Rollins 1 Styles 4-6 mm long; replum oblong, constricted; siliques densely pubescent, with appressed stellate hairs; ovules 2 on each side of the replum P. AUSTRALIS (Hook.) Gray Rorippa Scop. 1 Petals white (sometimes purple-tinged) , 3-6 mm long; plants aquatic R . NASTURTIUM-AQUATICUM (L.) Schinz & Thell. 1 Petals yellow, often less than 3 mm long 2 Pedicels (3) 4-12 mm long, usually at least as long as the fruits; silique ovate to oblong, 3-8 (12) mm long, 2-3 mm broad; stems mostly erect, 3-10 dm tall R. ISLANDICA (Oed.) Borbas 2 Pedicels mostly (1) 2-4 (7) mm long, usually markedly shorter than the fruits; silique from linear to oval, 2-15 mm long; stems commonly somewhat spreading to decumbent, rarely over 4 dm tall 3 Siliques oval to oblong-lanceolate, 2-6 (8) mm long, 2-2.5 mm broad, usually not arcuate R. OBTUSA (Nutt.) Britt. 3 Siliques linear, 6-14 mm long, 1-1.5 mm broad, usually arcuate R. CURVISILIQUA (Hook.) Bessey Sisymbrium L. 1 Pedicels slender, 7-20 mm long, much less thick than the fruit; siliques ascending to erect, 2-3.5 cm long S. LOESELII L. 1 Pedicels stout, 4-10 mm long, nearly as thick as the fruits; siliques spreading, rigid, 5-10 cm long S. ALTISSIMUM L. 130 Thelypodium Endl . 1 Cauline leaves mainly or e at base 1 Cauline leaves petiolate or itirely sessile and auriculate T. SAGITTATUM (Nutt . ) Endl. at least not auriculate T. INTEGRIFOLIUM (Nutt.)Endl. Thlaspi L. 1 Plant annual; style not more than 0.1-0.2 mm long T. ARVENSE L. 1 Plant perennial; style more than 0.3 mm long T. PARVIFLORUM A.Nels. CRASSULACEAE Stonecrop or Orpine Family Sedum L. Stonecrop 1 Flowers usually pink to purple (white); leaves mostly on the flowering stems, strongly flattened, persistent on the stems through the season, often toothed 2 Petals greenish or white to pink, mostly 8-10 mm long; flowers perfect S . RHODANTHUM Gray 2 Petals usually purple, never over 5 mm long; flowers mostly imperfect S. ROSEUM (L . ) Scop. 1 Flowers usually yellow, but sometimes drying to pinkish; leaves mostly basal along the creeping stems and sterile shoots, those of the flowering stems entire, generally deciduous by late anthesis S. LANCEOLATUM Torr . 131 SAXIFRAGACEAE Saxifrage Family 1 Pistil 4-carpellary , with 4 parietal placentae; stigmas almost or quite sessile; stamens 5, alternate with simple to fimbriate staminodia PARNASSIA 1 Pistil usually 2 or 3 (4 or 5) -carpellary and mostly with 2-3 axils or parietal placentae; stigmas usually borne on well-developed styles; stamens (3) 5-10; staminodia lacking 2 Ovary 1-celled and with usually 2 (less commonly 3) parietal to semibasal placentae 3 Styles or style branches 3; petals white or pinkish, laciniate; plants usually bulblet-bearing in the leaf axils or on the underground parts LITHOPHRAGMA 3 Styles or style branches normally 2; petals mostly either greenish or not laciniate; plants usually not bulblet-bearing 4 Petals entire 5 Flowers paniculate or thyrsoid, at least in the lower part of the often almost spicate inflores- cence; seeds finely echinulate in longitudinal rows; stamens usually 5; calyx never narrowly turbinate HEUCHERA 5 Flowers racemose; seeds rarely echinulate but if so then the calyx narrowly turbinate; stamens sometimes 3 or 10 CONIMITELLA WILLIAMSII (D.C.Eat.) Rydb. 4 Petals trifid to pectinately lobed MITELLA PENTANDRA Hook . 2 Ovary 2 (rarely 3-5) -celled, the placnetation axile 7 Styles partially connate; petals pink to deep red; calyx campnulate, usually reddish, (5) 6-10 mm long; leaves alternate, petiolate TELESONIX JAMESII (Torr . ) Raf. 7 Styles free above the ovuliferous portion of the ovary; petals usually white, but if (as rarely) pink or red (to purple) then either the calyx not at once companulate, red and so much as 6 mm long, or the leaves sessile and opposite SAXIFRAGA 132 Heuchera L. Alumroot 1 Calyx at anthesis mostly 2-3 mm long, regular, turbinate at the adnate base, the hypanthium flared and somewhat saucer-shaped, nearly as long as the spreading lobes, 1-1.3 mm long, lined with a thin glandular disc that more or less covers the almost completely inferior ovary; petals broadly elliptic to ovate H. PARVIFOLIA Nutt . 1 Calyx at anthesis usually well over 3 mm long, often oblique, generally campanulate at base and the hypan- thium cup-shaped, the lobes usually erect, most 1.5 mm long; hypanthium not gland-lined or if so the disc not covering the top of the ovary, the ovary usually no more than half inferior; petals often lanceolate to oblanceolate or wanting H . CYLINDRICA Dougl . Lithophragma Nutt. Prairie Star; Woodland Star 1 Seeds muricate; basal leaves glabrous or very sparsely pubescent; flowers mostly 2-5 (7), more or less corymbose at anthesis, later becoming "racemose", but the lower pedicels usually elongate and mostly 1.5-3 times as long as the calyx; cauline leaves often bulbiferous; petals usually 5-lobed L. BULBIFERA Rydb . 1 Seeds from nearly smooth (slightly wrinkled) to verru- cose or reticulate but never muricate; basal leaves moderately to copiously pubescent at least on the lower surface; flowers (sometimes as few as 4 or 5) usually 6-11, racemose, the lower pedicels mostly subequal to (to half again as long as) the calyx; cauline leaves not bulbiferous; petals often only 3-lobed 2 Calyx obconic-cyathiform , (3) 4-6 mm long at anthesis, mostly 6-10 mm long in fruit; ovary at least 2/3 inferior; petals commonly 3-lobed L. PARVIFLORA (Hook.) Nutt. 2 Calyx more nearly campanulate, 2-3 (3.5) mm long at anthesis and 3.5-5 mm long in fruit; ovary about 1/2 inferior; petals mostly 5 (7) -lobed L. TENELLA Nutt. 133 Parnassia L. Grass-of-Parnassus 1 Petals fringed on the lower half P. FIMBRIATA Konig. 1 Petals not fringed on the lower half 2 Leaf blades elliptic to elliptic-ovate, neither truncate nor cordate at the base; bract never at all clasping; petals usually 5-veined, mostly 4-7 mm long, rarely over 1.5 times as long as the calyx lobes P . PARVIFLORA DC . 2 Leaf blades from lanceolate to broadly ovate, often cordate; bract often clasping; petals 7- to 13-veined, mostly (6) 7-12 mm long, usually over 1.5 times as long as the calyx lobes P. PALUSTRIS L. Saxifraga L. Saxifrage 1 Leaves entire, mostly linear to lanceolate, usually 1 or more of them borne on the flowering stems below the inflorescence S. BRONCHIALIS L. 1 Leaves toothed to lobed, or if entire then all basal 2 Leaves (or some of them) with 3 apical cuspidate teeth, otherwise entire; petals white, usually reddish- to purplish-spotted; ovary not more than 1/5 inferior S . BRONCHIALIS L . 2 Leaves various, but not with 3 apical cuspidate teeth; petals various; ovary often more than 1/5 inferior 3 Flowers rarely more than 10; ovary usually at least 1/2 inferior at anthesis, if less than half inferior then most of the flowers replaced by bulbils; leaf blade generally not more than 2 cm in width or length; at least 2 or 3 of the leaves usually cauline 4 Leaves mostly narrowly oblong-cuneate to oblanceo- late-obovate, apically 3 (5-7) -toothed or -lobed into sometimes linear segments; some of the leaves (especially the basal) usually entire, the petiole (if any) generally broad, no longer than (and not clearly distinguishable from) the blade; bulbils lacking S . CAESPITOSA L . 4 Leaves (at least in part) reniform and rather evenly lobed, the basal ones with a slender petiole at least as long as the blade; bulbils usually pre- sent in the inflorescence or in the axils of the basal leaves S . CERNUA L. 134 Flowers usually more than 10; ovary often less than 1/2 inferior at anthesis; flowering stems usually leafless although sometimes bracteate; leaf blades usually well over 2 cm in length or width 5 Leaves more or less orbicular, or reniform or cordate at base, usually broader than long; filaments clavate S. ARGUTA D.Don 5 Leaves never reniform, mostly flabellate to lanceolate or obovate, usually much longer than broad; filaments often not clavate 6 Ovary less than half inferior at anthesis, the stamens inserted at the edge of a narrow bandlike gland or nectary surrounding but not covering the top of the ovary; plants mostly 1-2.5 (rarely to 3) dm tall; leaves regularly crenate-serrate; filaments often clavate S. OCCIDENTALIS Wats. 6 Ovary either over half inferior at anthesis or plants averaging over 3 dm tall; stamens inserted at the edge of a flattened, lobed disc that more or less covers the greater part of the ovuliferous portion of the pistil; leaves usually entire to sinuate or remotely denticulate, rather than regularly crenate-serrate; filaments not clavate 7 Flowering stems mostly 3-12 dm tall; inflorescence elongate and narrow to openly corymbose, rarely less than 1 dm long in late anthesis; leaves usually well over 5 cm long, slenderly ovate to oblanceolate , narrowed gradually to a sessile base or to a broadly winged petiole, neither the leaves nor the bracts ever reddish pilose-lanate S. OREGANA Howell 7 Flowering stems mostly not over 3 dm tall; inflor- escence often congested and less than 1 dm long even in fruit; leaves various, frequesntly with narrow petioles, they and the bracts sometimes reddish-pilose S. RHOMBOID EA Greene 135 GROSSULARIACEAE Currant or Gooseberry Family Ribes L. Currants and Gooseberries 1 Plants with spines or prickles at the nodes and often also along the internodes and on the fruit (these sometimes very few in number and reduced in size) 2 Free hypanthium shallowly cup-shaped or saucer- shaped; pedicels jointed below the ovary; racemes 3- to 15-flowered 3 Leaves copiously pubescent and more or less glandu- lar, 1-2.5 (4) cm broad; berries reddish; pedicels stout, rarely as much as twice as long as the bracts R. MONTIGENUM McClatchie 3 Leaves glabrous or only sparsely pubescent, never glandular, mostly 2-5 (7) cm broad; berries deep purple; pedicels slender, often at least twice as long as the bracts R. LACUSTRE (Pers.) Poir . 2 Free hypanthium tubular or campanulate, rarely cup- shaped but never saucer-shaped; pedicels not jointed near the ovary; racemes (1) 2- to 5-flowered 4 Stamens at least twice as long as the petals, some- times exceeding the extended sepals and conspicuously exserted R. INERME Rydb . 4 Stamens usually about as long as the petals, rarely as much as twice their length, never as long as the extended sepals and not conspicuously exserted even with the sepals reflexed R. SETOSUM Lindl. 1 Plants without prickles or spines; pedicels jointed below the ovary; flowers usually more than 5 (rarely as few as 2) per raceme (wild currants) 5 Free hypanthium campanulate to cylindric, never saucer-shaped or shallowly cup-shaped, at least as long as broad; ovary never with sessile, yellow, crystalline glands; flowers sometimes bright yellow 6 Hypanthium twice as long as the sepals; berry red R. CEREUM Dougl. 6 Hypanthium about equaling the sepals; berry bluish to black R. VISCOSISSIMUM Pursh 5 Free hypanthium saucer-shaped or very shallowly cup- shaped, broader than long; ovary sometimes with sessile, yellowish, crystalline glands; flowers never bright yellow R . HUDSONIANUM Richards 136 ROSACEAE Rose Family 1 Plants prickle-bearing; leaves pinnate; carpels several, enclosed within the globose to urceolate calyx (in fruit the calyx usually reddish and fleshy but the carpels themselves dry) ROSA 1 Plants not at once prickle-bearing, pinnate-leaved with several carpels enclosed within a globose to urceolate and ultimately fleshy calyx 2 Calyx adnate to the compound, 2- to 5-carpellary , more or less completely inferior ovary; ripe fruit fleshy; deciduous trees or shrubs 3 Leaves pinnate, the leaflets 5-17 SORBUS SCOPULINA Greene 3 Leaves simple AMELANCHIER ALNIFOLIA Nutt. 2 Calyx sometimes enclosing (but not adnate to) the 1 to several superior, 1-carpellary ovaries; ripe fruit dry to fleshy; plants herbaceous, shrubby, or rarely arborescent 4 Plant a shrub or small tree with large, deciduous, simple leaves and racemose flowers; pistils 1-5; fruit fleshy, drupaceous PRUNUS VIRGINIANA L . 4 Plant an herb or shrub, if shrubby the leaves often persistent, or lobed to compound; pistils 1-many, if 1 or 5 the fruit not drupaceous; flowers usually perfect 5 Leaves deciduous, simple, cuneate, deeply 3- toothed at the tip, otherwise entire, revolute- margined, greenish above , tomentose beneath; pistils 1 (2); erect, rigidly branched shrubs PURSHIA TRIDENTATA (Pursh)DC. 5 Leaves various but if cuneate and 3-toothed then the pistils more than 2, or plants herbaceous or evergreen 6 Plant a prostrate shrub with freely rooting branches leaves simple, crenate, evergreen; flowers single, pedunculate at branch ends DRYAS OCTOPETALA L . 6 Plants herbaceous or if shrubby then not trailing; leaves lobed to compound; flowers not single 7 Plant an erect, unarmed shrub with toothed or lobed (but never compound) leaves; pistils (1) 2-7 137 8 Leaves palmately 3- to 5-lobed; calyx usually stellate; fruit a somewhat inflated, several-seeded follicle, dehis- cent on both sutures PHYSOCARPUS MALVACEUS (Greene) Kuntze 8 Leaves pinnately many-lobed to toothed; calyx not stellate; fruit an achene or a follicle dehiscent only on the adaxial suture SPIRAEA 7 Plant often herbaceous but if an erect shrub then with com- pound leaves, or with prickles, or with numerous (more than 7) pistils 9 Stamens in ours 5; pistils usually 2-15 10 Leaves ternate; style laterally attached to the ovary SIBBALDIA PROCUMBENS L. 10 Leaves pinnately dissected; style subterminal IVESIA GORDONII (Hook.)T.&G. 9 Stamens 10 or more; pistils usually numerous 11 Stamens 10; anthers dehiscing lengthwise by slits on the inner (adaxial) face; perennials with pinnate leaves, the leaflets (5) 7-19, sometimes dissected HORKELIA FUSCA Lindl . 11 Stamens either more than 10 or, if 10, then the plants annuals or biennials with nondissected pinnae 12 Calyx ebracteolate; plants rhizomatous, stoloniferous , or trailing to erect, sometimes armed shrubs; mature fruit an aggregation of weakly coherent druplets RUBUS 12 Calyx bracteolate; plant various, but mostly herba- ceous, never armed; mature fruit an achene, often borne partially embedded in the fleshy receptacle 13 Receptacle enlarged and hemisperic, in fruit becom- ing spongy or fleshy; leaves usually ternate; stems strongly stolonous, freely rooting at the nodes FRAGARIA 13 Receptacle not becoming spongy or fleshy and strawbery-like; leaves various but if ternate the stems rarely if ever stolonous 14 Style slender, apical, straight to bent or genicu- late, persistent in fruit, although (if jointed) the upper segment usually deciduous; leaves usually lyrately pinnatifid GEUM 14 Style various, apically to laterally or almost basall inserted, straight, or only 1 segment, jointed to the achene and usually deciduous (or readily broken off); leaves various, but rarely if ever lyrate-pinnatifid POTENTILLA 138 Fragaria L . Strawberry 1 Leaves bright yellow-green and not glaucous on the upper surface, relatively thin and more or less veiny, the upper surface slightly bulged between the primary lateral veins and almost always somewhat pilose-silky; terminal tooth of the leaflets relatively well developed, usually project- ing beyond the uppermost lateral teeth; inflorescence commonly equaling or surpassing the leaves F. VESCA L. 1 Leaflets glaucous and somewhat bluish-green on the upper surface, rather thick and not very prominently veiny, the upper surface not bulged between the veins and nearly always glabrous; terminal tooth of the leaflets small, usually surpassed by the adjacent lateral teeth; inflores- cence commonly shorter than the leaves F . VIRGINIANA Duchesne Geum L . 1 Sepals reflexed in flower; hypanthium saucer-shaped, lined with a glandular disc at least on the lower half; styles strongly geniculate and jointed, the persistent (longer) portion hooked at the tip 2 Lower (persistent) segment of the style eglandular, glabrous or slightly hirsute near the base; terminal segment of the basal leaves somewhat larger than the main lateral lobes but similarly cuneate-based G. ALEPPICUM Jacq. 2 Lower (persistent) segment of the style somewhat glandular-pubescent; terminal segment of the basal leaves many times larger than the main lateral lobes and usually rounded to subcordate at base G. MACROPHYLLUM Willd. 1 Sepals ascending to erect; hypanthium turbinate to bowl-shaped, the lower half usually not disc-lined; styles often neither geniculate nor jointed and hooked on the persistent portion 3 Petals erect to convergent, the flower somewhat vase-shaped, usually closed; cauline leaves 2 (4) opposite, their bases more or less sheathing G. TRIFLORUM Pursh 139 3 Petals spreading, or at least not erect or convergent, the flower more nearly rotate; cauline leaves 1 to several, alternate G. ROSSII (R.Br.) Ser. Potentilla L. Cinquefoil; Five-finger 1 Flowers purple to deep red P. PALUSTRIS (L.) Scop. 1 Flowers white, cream, or yellow 2 Plant shrubby; ovaries and achenes strongly hirsute P. FRUTICOSA L. 2 Plant herbaceous; ovaries and achenes glabrous 3 Plants annuals or biennials or perhaps sometimes short-lived perennials but without rootstocks, the leaves never white-tomentose on the lower surface; stamens 10-20 4 Stems stiffly hirsute below with unicellular, more or less pustular based, spreading hairs; achenes usually strongly undulate-corrugate longitudinally; stamens (15) 20; petals mostly at least 3/4 as long as the sepals P. NORVEGICA L. 4 Stems soft-pubescent below, often with glandular or with multicellular or semitomentose pubescence; achenes smooth or very slightly striate; stamens mostly 10-15; petals usually less than 3/4 as long as the sepals P. BIENNIS Greene 3 Plants perennials, usually with well-developed rootstocks; leaves often white-tomentose on the lower surface; stamens 20-30 (40) 5 Flowers single on naked peduncles; plants strongly stoloniferous and with multipinnate leaves P. ANSERINA L. 5 Flowers usually several on more or less leafy flowering stems; plants not stoloniferous; leaves often ternate to palmate 6 Style slenderly fusiform, usually roughened at or below midlength, attached somewhat below midlength of the ovary; leaves pinnate, with 5-11 leaflets; stamens about 25, sometimes up to 40 140 7 Cymes narrow and strict (often much elongate) , the lateral branches almost erect; sepals mostly 6-8 mm long at anthesis; petals pale yellow ("white"), usually equaling to slightly exceeding (by 1-2 mm) the sepals; plants mostly over 4 dm tall P . ARGUTA L . 7 Cymes usually open to diffuse, sometimes glomerate, the lateral branches not tightly appressed; sepals often less than 6 mm long; petals pale to deep yellow, if pale yellow ("white") then usually shorter than the sepals or the plants mostly less than 4 dm tall or the inflorescence open P . GLANDULOSA Lindl . 6 Style usually tapered from the base, or filiform or attached near the top of the ovary; leaves palmate or if pinnate often with more than 11 leaflets; stamens often 20 8 Basal leaves predominately odd-pinnate, at least some with 5 or more leaflets, few (if any) digitate although occasionally a few ternate 9 Leaflets usually oblong, (1) 2-5 cm long, grayish- tomentose beneath and often grayish-strigose on theuppe surface, rarely toothed over halfway to the midvein; plants often over 3 (and rarely less than 2) dm tall 10 Anthers 0.5-0.7 mm long; leaves usually unmis- takably pinnate P . HIPPIANA Lehm . 10 Anthers over 0.8 mm long; leaves subdigitate P. GRACILIS Dougl. 9 Leaflets usually less than 2 cm long or otherwise not as above, often either greenish or dissected much more than halfway to the midvein; if gray or tomentose then the plants usually less than 2 dm tall 11 Pinnae mostly 5-7, crowded, often in part digi- tate, obovate to oblong; most]y 1-3 (5) cm long, usually greenish on both surfaces (never tomen- tose); plants (1) 1.5-4.5 dm tall P. DIVERSIFOLIA Lehm. 11 Pinnae either more numerous, or tomentose at least beneath; plants often less than 1.5 dm tall P. OVINA Macoun 8 Basal leaves predominantly digitate, although some- times with only 3 leaflets (ternate) 141 12 Flowers mostly well under 1 cm broad, born on nearly- filiform pedicels in leafy-bracteate cymes; plants with numerous, ascending, conspicuously leafy stems; leaf- lets 0.5-2.5 cm long, greenish above, whitish-lanate beneath, toothed well over halfway to the midvein; style thickened and glandular at the base P . ARGENTEA L . 12 Flowers mostly over 1 cm broad, born in inconspicuously bracteate cymes; plants usually with most of the leaves basal rather than cauline; leaves various but never greenish above and lanate beneath if the flowers are less than 1 cm broad; styles often filiform and not warty glandular at the base 13 Plants alpine (or subalpine), (1) 1.5-4.5 dm tall; leaflets mostly 1-3.5 (to 5) cm long, usually greenish or nearly equally grayish-sericeous on both surfaces; anthers mostly 0.4-0.6 mm long P. DIVERSIFOLIA Lehm. 13 Plants mostly from the lowlands to medium elevations in the mountains, as much as 8 dm tall; leaflets (2) 3-8 (12) cm long, often tomentose beneath or much paler on the lower than on the upper surface; anthers mainly 0.8-1.3 mm long P. GRACILIS Dougl. Rosa L. Rose 1 Stems more or less bristly with slender prickles, the infrastipular prickles, if present, not differentiated from the others R . ACICULARIS Lindl . 1 Stems mostly with well-defined infrastipular prickles, or sometimes nearly unarmed R. WOODSII Lindl. Rubus L . Bramble; Blackberry; Raspberry 1 Plants unarmed R . PARVIFLORUS Nutt. 1 Plants armed with bristlelike to broad-based and often curved prickles R . IDAEUS L. 142 Spiraea L. 1 Petals pink to red; inflorescence and the lower surface of the leaves often puberulent S. DENSIFLORA Nutt. 1 Petals white or with only a pale pinkish or lavender tinge; plant glabrous or merely ciliolate on the leaves and bracts S . BETULIFOLIA Pall. LEGUMINOSAE Pea Family 1 Stamens distinct; leaves trifoliolate; flowers yellow, racemose; pod several times as long as the calyx THERMOPSIS MONTANA Nutt. 1 Stamens more or less connate; leaves various but if trifoliolate then the flowers other than yellow and racemose or the pods barely exceeding the calyx 2 Herbage thickly dotted with small glands; leaflets either 3 (less commonly 5) or the fruits covered with hooked spines GLYCYRRHIZA LEPIDOTA Pursh 2 Herbage seldom at all glandular-punctate but if so then the fruits neither burlike nor the leaves trifoliolate 3 Leaves trifoliolate, usually shallowly toothed; mature fruits either spirally coiled or more or less completely enclosed within the calyx 4 Pod falcate to coiled, very heavily veined, some- times prickly; flowers either few and borne in axillary, pedunculate, small heads, or more numerous and racemose, yellow or purplish MEDICAGO 4 Pod neither falcate to coiled nor spiny; flowers mostly numerous in heads or racemes, often other than yellow or purplish 5 Flowers in long narrow racemes, white or yellow; plants usually 0.5-3 m tall MELILOTUS 5 Flowers in heads or short spikes, mostly other than yellow but if yellow then the plants usually decumbent or at least much less than 0.5 m tall TRIFOLIUM 3 Leaves seldom trifoliolate but if so then the leaflets entire or the pods elongate beyond the calyx and not coiled 143 6 Leaves palmately compound; leaflets (4) 5-17 7 Flowers in elongate racemes; stamens monadelphous LUPINUS 7 Flowers in heads or headlike spikes or racemes; stamens diadelphous TRIFOLIUM 6 Leaves not palmately compound 8 Pods much constricted between the seeds, breaking crosswise into 1-seeded segments; keel sometimes equaling or considerably exceeding the wings HEDYSARUM 8 Pods not conspicuously constricted between the seeds, dehiscing lengthwise rather than breaking crosswise; keel usually shorter than the wings 9 Leaves even-pinnate, the rachis prolonged as a slender bristle or a simple or branched tendril; plants often scandent VICIA AMERICANA Muhl . 9 Leaves odd-pinnate or at least with a terminal leaf- let, the rachis not prolonged as a bristle or tendril (although the terminal leaflet sometimes confluent with rachis); plants not scandent 10 Leaves trifoliolate; pods pubescent; flower yellow MEDICAGO 10 Leaves pinnate; leaflets usually at least 5; pods and flowers various 11 Keel of the corolla abruptly narrowed to a beaklike point; plants usually without leafy stem OXYTROPIS 11 Keel of the corolla not abruptly beaked; plants mostly with leafy stems ASTRAGALUS Astragalus L. Locoweed; Milk Vetch; Rattlepod KEY USABLE ON FLOWERING MATERIAL 1 Leaflets 5-11, linear-elliptic, all continuous with the rachis and mucronate or pinulose at the tip; raceme 1- to 3-flowered short-pedunculate or subsessile, the small flowers (banner 4-8 mm long) usually appearing axillary; pod less than 1 cm long, 1-locular A. KENTROPHYTA Gray 1 Leaflets not as above, if all continous with the rachis, then the racemes several-flowered and long-pedunculate and the flowers larger 2 Pubescence of the herbage dolabriform A. CANADENSIS L. 144 Pubescence basifixed, all leaflets jointed to the rachis, the leaves imparipinnate 3 Stipules at the lowest nodes (and sometimes at all) fully amplexicaul and connate opposite the petiole, or (if the lowest nodes bladeless) the stipules united around the stem as a low collar or sheath 4 Banner (measured along the curvature of the midvein) over 15 mm long 5 Stems and herbage villous-hirsute with horizontally spreading hairs up to 1-2 mm long; pod pendulous, stipitate, glabrous, 2-locular A. DRUMMONDII Hook. 5 Stems and herbage pilose or strigillose, the hairs either appressed or, if loose, then less than 1 mm long; pod either erect or 1-locular (A. dasyglottis) A. AGRESTIS Dougl . 4 Banner not over 15 mm long 6 Banner 10-15 mm long 7 Wings deeply bidentate at the apex; pod stipi- tate, laterally compressed A. ABORIGINUM Richards. 7 Wings entire or at most shallowly truncate- emarginate 8 Flowers erect, subsessile, closely crowded in ovoid heads; caudex subterranean, with few to numerous partially buried branches; calyx tube 4-7 mm long; pods hirsute (A. dasyglottis) A. AGRESTIS Dougl. 8 Flowers variously oriented, but if erect then loosely racemose or plant otherwise not as in A . agrestis 9 Stems arising singly or few together from slender, widely creeping and adventitiously rooting, subterranean caudex branches; plants of cool or moist soils in the mts . A. ALPINUS L. 9 Stems arising together from the crown or caudex; if the root crown subterranean the caudex branches not rooting and the plants of lower elevations A. MISER Dougl. 6 Banner less than 10 mm long 10 Keel petals 2.5-6 mm long 145 11 Immature pod nearly always bearing some black or fuscous hairs A . EUCOSMUS Robins. 11 Immature pod strigillose with white hairs exclu- sively, or glabrous 12 Stems mostly erect; flowers white; pod stipitate; stipules blackening A . TENELLUS Pursh 12 Stems diffuse or prostrate, often matted, if erect the petals purplish; pod sessile; stipules not blackening A. VEXILLIFLEXUS Sheld. 10 Keel petals over 6 mm long 13 Wings deeply bidentate at apex A. ABORIGINUM Richards. 13 Wings entire or obscurely truncate-emarginate 14 Stems arising singly or few together from slender, widely creeping and adventitiously rooting, subterranean caudex branches; plants of moist or cool soils in the mts . A. ALPINUS L. 14 Stems arising together from the root crown or caudex; if the root crown subterranean then the plants of dry foothills and prairies or alpine scree and ridges A. MISER Dougl. 3 Stipules petiolar or petiolar-cauline , variably decurrent- amplexicaul but not united opposite the petiole 15 Banner over 15 mm long 16 Ovary and pod glabrous A. DRUMMONDII Hook. 16 Ovary and pod pubescent 17 Racemes not over 10-flowered; leaflets uniformly and densely silvery-strigose or softly villous- tomentose on both sides A. PURSHII Dougl. 17 Racemes usually over 10-flowered, or if rarely less than 10-flowered, then the herbage green and the leaflets glabrous or medially glabrescent above A. CIBARIUS Sheld. 15 Banner not over 15 mm long 18 Banner 10-15 mm long 146 19 Cauline stipules very large, foliaceous, becoming papery, several-nerved, deflexed; leaflets 9~15, ample and thin-textured, 1.5-6 cm long; pod pendu- lous, stipitate, bladdery, membranous; plants of stream banks and mountain woods, mesophytic A . AMERICANUS (Hook . ) M .E .Jones 19 Cauline stipules not foliaceous; leaflets mostly less than 1.5 cm long; pod sessile if inflated; plants xerophytic A. PURSHII Dougl. 18 Banner less than 10 mm long 20 Leaflets 5-7 (or in var . lagopinus as many'as 11), densely pannose-tomentose; pod thickly hirsute- tomentose, 1-celled A. PURSHII Dougl. 20 Leaflets more than 7; if plant tomentose then the ovary nearly or quite 2-celled A. EUCOSMUS Robins. KEY USABLE ON PLANTS IN FRUIT 1 Plant prostrate, densely matted; leaflets linear-filiform , 3-10 mm long, silvery-strigose , acerose; flowers 1 or 2 (3) in each raceme; pods 1- to 4-seeded, indehiscent, about 5 mm long A . KENTROPHYTA Gray 1 Plant not at once prostrate and matted and with linear- filiform, acerose leaflets, only 1 or 2 flowers per raceme, and 1- to 4-seeded, indehiscent pods 2 Inflorescence, even in fruit, a head-like spike nearly as broad as long; calyx often black-hairy; corolla purplish, about 15 mm long; pod erect, about 1 cm long; ovoid, grayish- or blackish-pilose, cordate in cross section due to the complete intrusion of the lower suture; plant rhizomatous (A. dasyglottis) A. AGRESTIS Dougl. 2 Inflorescence seldom capitate or as broad as long, but if so, plants then not otherwise like A . agrestis 3 Pods woolly or villous with long white or grayish hairs that almost or quite conceal the surface, usually woody or coriaceous in texture with the lower suture intruded to divide the cavity more or less completely into 2 cells A. PURSHII Dougl. 147 3 Pods neither woolly nor with the surface concealed by the often dense but short, or less abundant longer pubes- cence, the texture of the pod various, the lower suture often not intruded 4 Pods inflated, thin and papery, and not at all woody, ellipsoid, acute at each end, 2-3 cm long, stipitate flowers ochroleucous A. AMERICANUS (Hook.) M .E .Jones 4 Pods not inflated, or if inflated then tough and often woody usually elliptic to linear or oblong in outline , often strongly compressed or obcompressed 5 Pod not visibly stipitate, the stalk (if any) shorter than the calyx and concealed by it 6 Legumes 1-celled with the lower suture very slightly (if at all) intruded, either round in section or, more commonly, compressed 7 Pod 4-10 (12) mm long, elliptic-oblong, acute; leaflets 1-4 mm broad, grayish-hairy; flowers 4-8 (10) mm long A. VEXILLIFLEXUS Sheld. 7 Pod over 10 mm long and (usually) linear or oblong, or leaflets either over 4 mm broad or not grayish-hairy, or flowers over 10 mm long 8 Legume obliquely elliptic in outline, 8-12 mm long A. EUCOSMUS Robins. 8 Legume linear or narrowly oblong in outline, usually well over 12 mm long A. MISER Dougl. 6 Legumes either partially to completely 2-celled (the lower suture at least somewhat intruded) or more or less cordate, reniform, or obcompressed in section 9 Flowers (15) 30-150 borne in spikelike congested racemes, 12-18 mm long; pedicels about 1 mm long; pubescence of the calyx and stems appressed, dolabriform; stipules membranous, mostly connate opposite the petioles; pod 8-20 mm long, seldom over twice as long as the calyx, the lower suture deeply sulcate A . CANADENSIS L. 9 Flowers seldom borne in spikelike racemes; pubescence usually basi-fixed; stipules seldom connate; pod mostly over 1 cm long 10 Legume gray- and black-hairy, less than 13 mm long, pendulous; flowers 6-9 mm long A. EUCOSMUS Robins. 148 10 Legume not at once black-hairy, less than 13 mm long, and pendulous, when the flowers are less than 10 mm long • A. CIBARIUS Sheld. 5 Pod stipitate, the body narrowed to a stalk at the mouth of the calyx tube or outside the calyx, this stipe at least as long as the calyx tube and visible at maturity of the fruit 11 Pod from strongly compressed to round in cross section, strictly 1-celled, the lower suture rarely protruding into the cavity, the partition (if any) rudimentary and less than 1/4 the height of the cavity 12 Rachis of leaves seldom as much as 5 cm long; leaflets usually 2-5 mm broad A. ABORIGINUM Richards. 12 Rachis of leaves usually well over 5 cm long; leaf- lets often less than 2 mm broad A. TENELLUS Pursh 11 Pod round, cordate, or triangular in section, or obcompressed, usually with the lower suture rather deeply sulcate, if pod round or compressed then with a partition extending at least 1/3 across the cavity 13 Pod and calyx black-hairy, pod pendulous, the body 8-12 mm long; plant rhizomatous A. ALPINUS L. 13 Pod and calyx not at once black-hairy when the plant is rhizomatous and has reflexed pods with the body of the pod less than 15 mm long A. DRUMMONDII Hook. Hedysarum L. 1 Flowers yellowish to nearly white H. SULPHURESCENS Rydb . 1 Flowers pink or carmine to purplish H. BOREALE Nutt. 149 Lupinus L . Lupine 1 Either the banner conspicuously hairy over much of the abaxial (back) surface, or the calyx spurred 2 Calyx not spurred; either the pubescence of the banner extending to the upper third, or the flowers less than 9 mm long, or the wing petals not pubescent on the upper half L . SERICEUS Pursh 2 Calyx spurred; pubescence of the banner usually not extending to the upper third; wing petal often hairy on the upper half; flowers at least 9 mm long L. CAUDATUS Kell. 1 Neither the banner conspicuously hairy on the back nor the calyx spurred; pubes cence of the banner, if any, largely concealed by the calyx 3 Banner slightly or moderately reflexed from the wings and keel, consequently (or because of the small-sized flowers) the banner index only 2-10; plants caulescent, the stems rarely less than 1 (and usually over 2) dm long exceeding the lower petioles (including A. alpestris, A. monticola, A. parviflorus) L. ARGENTEUS Pursh 3 Banner mostly so well reflexed (or the flowers so large) that the banner index averages well over 10 (usually at least 15), sometimes the index less than 15, but then the plants subacaulescent, with stems rarely over 1 dm long and usually shorter than the longer petioles 4 Plants low and spreading, usually less than 3 dm tall, the leafy stems generally shorter than the scapes and racemes; upper calyx lip bidentate for 1/2 of the length or more L . LEPIDUS Dougl. 4 Plants usually well over 3 dm tall, mostly with leafy stems longer than the peduncles and equal to the longest basal petioles; upper calyx lip sub- entire to deeply bidentate 5 Leaflets pubescent (usually strigose) on the upper surface, mostly abruptly acuminate to apiculate, from linear-oblanceolate, 2-4 (7) cm long, 2-6 (14) mm broad; stems only slightly or not at all fistulose L. WYETHII Wats. 150 5 Leaflets glabrous on the upper surface, mostly rounded or acute, elliptic-oblanceolate , (3) 4-10 (15) cm long, 10-25 mm broad; stems often strongly fistulose L. POLYPHYLLUS Lindl . Medicago L. 1 Plant perennial, deep-rooted; flowers blue, 6-10 mm long fruits unarmed M . SATIVA L . 1 Plant annual, rather shallow-rooted; flowers yellow, less than 6 mm long; fruits often armed M . LUPULINA L . Melilotus Mill. Sweet Clover; Melilot 1 Corolla white M . ALBA Desr. 1 Corolla yellow M . OFFICINALIS (L . ) Lam . Oxytropis DC. Nom . Conserv. Stemless Loco 1 Stipules foliaceous, adnate to the base of the petiole for only 1-3 mm, the free portion lanceolate 6-12 mm long; pods pendulous; plants often with short leafy stems O. DEFLEXA (Palls.) DC. 1 Stipules adnate to the base of the petiole for half their length or more; pods spreading or (more commonly) erect; plants acaulescent 2 Plant more or less glandular-verrucose and often viscid, the warts especially evident on the calyx teeth (sometimes lacking elsewhere); flowers cream to purple O. VISCIDA Nutt. 2 Plant neither viscid nor glandular-verrucose 3 Flowers purple or reddish-purple O. LAGOPUS Nutt. 3 Flowers white to yellowish, the keel sometimes purple-tinged 4 Pod fleshy before maturity, then hardened and bony, the dried wall nearly 1 mm thick; flower mostly well over 15 mm long O. SERICEA Nutt. 151 4 Pod more membranous than fleshy, the dried wall scarcely 0.5 mm thick; flowers frequently less than 15 mm long O. CAMPESTRIS (L.) DC. Trifolium L . Clover 1 Flowers subtended by a true involucre T. PARRYI Gray 1 Flowers not subtended by a true involucre, although sometimes the stipules of the upper leaves somewhat involucral 2 Calyx glabrous or only very sparsely pubescent with scattered hairs 3 Flowers 5-9 mm long; heads axillary 4 Corolla white or slightly pinkish-tinged; plant stoloniferous; calyx glabrous; leaflets usually retuse to obcordate; stipules 3-10 mm long T. REPENS L. 4 Corolla usually pink to reddish (white); plant usually not stoloniferous, the stems ascending to erect; calyx with a few hairs at the base of the teeth; leaflets frequently rounded; stipules 5-20 mm long T. HYBRIDUM L. 3 Flowers at least 10 mm long; heads often terminal and solitary 5 Plant glabrous, caespitose or nearly so, the leafy stems scarcely 5 cm tall; high montane in the Rocky Mts . T . HAYDENII Porter 5 Plant either pubescent or with leafy stems over 5 cm tall T . LONGIPES Nutt . 2 Calyx strongly pubescent to villous or plumose 6 Heads sessile or very short-pedunculate, 50- to 200-flowered; peduncles shorter than the subtending leaves; stipules of the upper leaves forming a false involucre T . PRATENSE L. 6 Heads pedunculate, sometimes few-flowered; ped- uncle either longer than the leaves , or the upper stipules not involucral T. LONGIPES Nutt. 152 GERANIACEAE Geranium Family 1 Leaves pinnately compound; fertile stamens 5 ERODIUM CICUTARIUM (L . ) L'Her. 1 Leaves palmately-lobed or -divided; fertile stamens usually 10 GERANIUM Geranium L . Crane's-bill; Wild Geranium 1 Plants annual or biennial; petals less than 12 mm long; seeds smooth or reticulate-pitted G. BICKNELLII Britt. 1 Plants perennial; petals at least 12 mm long; seeds reticulate 2 Petals white or pale pink, with pinkish or purplish veins , pilose about half their length on the inner face; inflorescence pilose with glandular, purplish-tipped hairs; beak of the stylar column no longer than the free lobes of the stigma G. RICHARDSONII Fisch . &Trautv . 2 Petals pink to deep magenta-purple, rarely white, usually pilose on the inner face for not more than 1/3 their length; inflorescence eglandular or glandular with yellowish hairs; beak of the stylar column considerably longer than the stigmatic lobes G. VISCOSISSIMUM F. &M. EUPHORBIACEAE Spurge Family Euphorbia L. Spurge 1 Seeds coarsely transcorrugated; leaves thick-margined, linear-oblong, entire to denticulate; involucres more or less turbinate E. GLYPTOSPERMA Engelm . 1 Seeds smooth to wrinkled or pitted but not coarsely transcorrugated; leaves more nearly obovate-oblong or ovate-oblong, the margins serrulate but not thickened; involucres approximately campanulate E. SERPYLLIFOLIA Pers. 153 ANACARDIACEAE Sumac Family Rhus L. Sumac 1 Fruit abundantly reddish-hairy; petals pilose on the inner surface R . TRILOBATA Nutt. 1 Fruit nearly or quite glabrous, not red; petals glabrous (Toxicodendron) R . RADICANS L . RHAMNACEAE Buckthorn Family 1 Fruit fleshy; flowers greenish; petals short-clawed or lacking RHAMNUS ALNIFOLIA L'Her. 1 Fruit capsular; flowers white to blue; petals long-clawed CEANOTHUS VELUTINUS Dougl. MALVACEAE Mallow Family 1 Petals mostly over 2 cm long; leaves large and suggestive of those of the grape; carpels smooth on the sides, dehis- cent full length ILIAMNA RIVULARIS (Dougl . ) Greene 1 Petals mostly less than 2 cm long; leaves small and often deeply lobed to incised; carpels strongly reticulate on the sides below the middle SPHAERALCEA COCCINEA (Pursh) Rydb. HYPERICACEAE St . John's Wort Family Hypericum L. St. John's Wort 1 Sepals linear-lanceolate, 3-5 times as long as broad, mostly acute; leaves lanceolate to obovate-oblanceolate or narrowly spatulate-oblanceolate; seeds brownish, usually over 1 mm long, distinctly pitted in longitudinal rows , not striate H . PERFORATUM L . 1 Sepals triangular to ovate-lanceolate, less than 3 times as long as broad, rounded to acute; leaves ovate-oblong to ovate; seeds yellowish, 1 mm long or less, indistinctly reticulate-alveolate but not pitted, apparently longitudi- nally striate H. FORMOSUM H.B.K. 154 VIOLACEAE Violet Family Viola L. Violet 1 Petals predominantly white, often with bluish or purplish shading, but not yellow 2 Plants producing annual, flower-bearing, elongate to short and tufted-leafy stems V. CANADENSIS L. 2 Plants not producing annual floriferous stems, the flowers pedunculate on the main rhizome 3 Petals generally tinged with some violet or blue on the back, usually at least 8 mm long; stolons well developed; leaves mostly over 2.5 cm broad, glabrous V. PALUSTRIS L. 3 Petals seldom other than pure white (aside from the purplish pencilling), often less than 8 mm long; stolons present or absent; leaves often less than 2.5cm broad V . MACLOSKEYI Lloyd 1 Petals predominantly blue, violet, or yellowish, rather than white 4 Corolla bluish to purple, definitely not yellow 5 Stolons present, very slender and elongate; erect leafy stems lacking, the leaves arising from the rhizomes; plants of very moist or boggy ground V. PALUSTRIS L. 5 Stolons absent or if present the plants with erect leafy stems 6 Aerial stems well developed, often longer than the leaves and peduncles , floriferous on the upper 2/3; the leaves more or less acuminate V. CANADENSIS L. 6 Aerial stems lacking or at least shorter than the peduncles which are borne mainly on the rhizomes; rarely the stems longer than the peduncles 7 Head of the style not bearded; plants glabrous, caulescent or acaulescent V. NEPHROPHYLLA Greene 7 Head of the style bearded; plants glabrous or hairy, usually caulescent V . ADUNCA Sm . 4 Corolla partially or wholly yellow 155 8 Flowers from near the tip of erect leafy stems that are naked below; leaves mostly large, thin, and cordate- based V. CANADENSIS L. 8 Flowers not confined to the tip of erect branches, the stems leafy and floriferous below 9 Leaf blades coarsely veined, usually not over 4 cm long, coarsely few-toothed or -lobed, not regularly serrate or dentate, often glaucous and more or less purplish, at least along the veins; upper petals deep purple on the back; capsules puberulent V. PURPUREA Kell. 9 Leaf blades not coarsely veined, from entire to finely or obscurely serrate or dentate, often well over 4 cm long, usually not glaucous and not noticeably purplish, even along the veins; upper petals often not purple on the back; capsules glabrous or puberulent V. NUTTALLII Pursh LOASACEAE Blazing-Star Family Mentzelia L. Blazing Star 1 Plants biennial to perennial; petals 1.5-8 cm long; seeds flattened 2 Petals apparently 10, the inner five (staminodia) not quite so broad as the outer (true) petals; floral bracts adherent to the ovary; seeds thin-margined but not winged M. DECAPETALA (Pursh) Urb. & Gilg. 2 Petals 5, the five outer stamens sometimes flattened and somewhat petaloid, but much narrower than the true petals; floral bracts not adherent to the ovary; seeds distinctly wing-margined M . LAEVICAULIS (Dougl . ) T.&G. 1 Plants annual; petals less than 1.5 cm long; seeds not flattened 3 Floral bracts mostly ovate-lanceolate to ovate; inflor- escence congested; capsules linear; seeds uniseriate throughout, prismatic, grooved on the vertical margins, so obscurely tuberculate-muricate as apparently to be smooth, even when viewed with a lOx lens M . DISPERSA Wats . 156 3 Floral bracts narrowly to broadly lanceolate; inflores- cence not congested; capsules usually noticeably broad- ened upward; seeds obviously tuberculate-muricate when viewed with a lOx lens, and prismatic and often grooved on the vertical angles in the lower portion of the capsules, those above arranged and shaped irregularly and not grooved on the angles M. ALBICAULIS Dougl . CACTACEAE Cactus Family Opuntia Mill . Prickly-Pear Cactus 1 Joints of the stems not greatly flattened, often nearly as thick as broad, usually less than 5 cm long, readily detached from the plant; spines rather strongly barbed; areoles usually noticeably white-woolly; flowers yellow O. FRAGILIS (Nutt.) Haw. 1 Joints of the stems conspicuously flattened, the larger ones 5-13 cm long, not readily detached from the plant; spines only slightly barbed; areoles usually with rusty wool, if any; flowers yellow to reddish O. POLYACANTHA Haw. ELAEAGNACEAE Oleaster Family 1 Leaves alternate; plants perfect flowered; stamens 4 ELAEAGNUS COMMUTATA Bernh. 1 Leaves opposite; plants dioecious; stamens 8 SHEPHERDIA CANADENSIS (L.)Nu ONAGRACEAE Evening Primrose Family 1 Fruit nutlike , hardened, indehiscent, 1- to 4-seeded, 4-angled and flat-sided GAURA PARVIFLORA Dougl. 1 Fruit capsular, many-seeded, dehiscent, usually more or less terete 2 Seeds with a conspicuous tuft of long hairs at the tip; plants often growing along streams or on moist soil; leaves often opposite EPILOBIUM 157 2 Seeds glabrous or very finely strigose-puberulent; plants mainly from dry hills or drying mud flats; leaves nearly always alternate 3 Ovary 2-celled, slender; plants usually very freely branched; flowers small, white to pinkish, the petals up to 5 mm long GAYOPHYTUM 3 Ovary 4-celled; habit and flowers diverse, the petals often well over 5 mm long OENOTHERA Epilobium L . Willow Herb 1 Stigma 4-cleft; petals either yellow or at least 1 cm long (sometimes both yellow and over 1 cm long) 2 Petals yellow E . SUFFRUTICOSUM Nutt . 2 Petals pink to purple (white) 3 Leaves (in part at least) usually over 8 cm long; plants mostly over 4 dm tall, strongly "rhizomatous"; styles exceeding the stamens, hairy near the base; floral bracts much reduced, linear; racemes elongate, usually at least 15-flowered E. ANGUSTIFOLIUM L. 3 Leaves less than 8 cm long; plants usually less than 4 dm tall, not rhizomatous; styles shorter than the stamens, glabrous; floral bracts similar to the leaves although somewhat reduced; racemes usually not more than 15-flowered E. LATIFOLIUM L. 1 Stigma usually entire or, if with short lobes, the petals never yellow (sometimes creamy-white) and seldom as much as 1 (rarely to 1.3) cm long 4 Plant an annual, taprooted, usually growing on well- drained soil; epidermis on the lower portion of the stem usually exfoliating E . PANICULATUM Nutt . 4 Plant a perennial, usually rhizomatous, generally growing in moist places; lower epidermis mostly not exfoliating 5 Plants usually grayish-strigillose , at least above, producing turions; leaves linear to narrowly lanceo- late, (1) 2-6 cm long, 1-4 (8) mm broad; petals white to pink E . PALUSTRE L . 5 Plants not grayish-strigillose, or if so not producing turions or the leaves not linear or the petals not white 158 6 Turions usually present; seeds often papillate E. GLANDULOSUM Lehm . 6 Turions absent; seeds various 7 Plants glabrous throughout or with minute pubescence in the inflorescence or on the ovary, usually distinctly glaucous, often matted at the base; leaves lanceolate to ovate, entire to denticulate E. GLABERRIMUM Barbey 7 Plants usually pubescent, not glaucous 8 Stems usually well over 3 dm tall and freely branched above the middle; rhizomes short or lacking; leaves often well over 4 cm long, usually denticulate to serrate; seeds conspicuously crested-papillate in numerous parallel longitudinal lines; coma white E. WATSONII Barbey 8 Stems seldom over 3 dm tall, simple or with a few basal branches; rhizomes usually well developed and the plants matted; leaves seldom over 4 cm long, often entire; seeds smooth or the papillae very small and not in distinct rows; coma usually dingy E. ALPINUM L. Gayophytum Juss . 1 Capsules nearly or quite sessile, only slightly or not at all constricted between the seeds; plants basally branched, very leafy above, the leaves commonly much longer than the internodes G. HUMILE Juss. 1 Capsules pedicelled, usually constricted between the seeds; plants commonly branched above, the internodes often longer than the leaves G. RAMOSISSIMUM Nutt. Oenothera L. Evening Primrose 1 Plants mostly without leafy stems, the flowers borne among the rosettes of leaves, stems (if present) short and concealed by the leaves and flowers; hypanthium several times as long as the ovary 2 Petals white or yellow, aging to pink or purple, 1-5 cm long; stigma lobes linear, usually at least 3 mm long; hypanthium deciduous from the developing fruit 159 3 Petals white O . CAESPITOSA Nutt. 3 Petals yellow O. FLAVA (Nels.) Garrett 2 Petals yellow, seldom aging to purple, less than 2 cm long; stigmas globose or discoid; hypanthium filiform, persistent on the fertile portion of the ovary, flared only at the top O . BREVIFLORA T . & G . 1 Plants with leafy flowering stems; hypanthium often shorter than the mature capsules; annuals or perennials 4 Petals white or pinkish and more than 1 cm long O. NUTTALLII Sweet 4 Petals either yellow or less than 1 cm long O. STRIGOSA Mack. &Bush. UMBELLIFERAE Parsley Family ARTIFICIAL KEY TO THE GENERA 1 Leaves all simple, entire BUPLEURUM AMERICANUM Coult. & Rose 1 Leaves or most of them compound or very deeply cleft 2 Leaves or many of them with more or less well-defined leaflets, not dissected into small and narrow segments 3 Leaflets 3, very large, mostly 1-4 dm long and wide HERACLEUM LANATUM Michx. 3 Leaflets usually more than 3, seldom as much as 1 dm wide 4 Plants perennial from fibrous or fleshy-thickened, fascicled roots, without a taproot or well-developed caudex SANICULA GRAVEOLENS Poepp 5 Base of the stem thickened, hollow, and with well- developed transverse partitions; some of the roots usually tuberous-thickened; primary lateral veins of the leaflets tending to be directed to the sinuses between the teeth CICUTA DOUGLASII (DC.) Coult. & Rose 5 Base of the stem without transverse partitions; roots not tuberous-thickened; veins not directed to the sinuses 6 Ribs of the fruit inconspicuous, mature fruit 1.5-2 mm long; margin of leaflets or ultimate leaf segments irregular, crenate to incised; plant often stoloniferous BERULA ERECTA (Huds.) Cov . 160 6 Ribs of the fruit prominent, more or less corky- thickened; fruit 2-3 mm long; margin of leaflets or ultimate leaf segments evenly- serrulate to serrate SIUM SUAVE Walt. 4 Plants annual, biennial, or perennial from a taproot or stout caudex 7 Plants low, scapose or subscapose (or with a pseudo scape) , up to 2 dm tall LOMATIUM 7 Plants taller and usually more or less leafy-stemmed 8 Biennial weed; flowers yellow; fruit unarmed PASTINACA SATIVA L . 8 Perennials, not weedy 9 Fruit dorsally flattened 10 Stylopodium well developed; flowers white or occasionally pinkish ANGELICA 10 Stylopodium obsolete or nearly so; flowers yellow LOMATIUM 9 Fruit subterete or flattened laterally 11 Fruit linear or linear-oblong to calvate, not at all winged, 8-22 mm long; leaves always with well-defined leaflets OSMORHIZA 11 Fruit broader and often shorter, often some of the ribs winged; leaflets not always well defined LIGUSTICUM 2 Leaves more or less dissected into mostly rather small and narrow ultimate segments, without well-defined leaflets 12 Plant a robust, short-lived perennial weed, 1-2 m tall, when well developed, with glaucous stems, yellow flowers, and finely dissected leaves, the ultimate segments well under 1 mm wide FOENICULUM VULGARE Mill . 12 Plants distinctly otherwise, differing in one or more respects from the above 13 Plant a weedy European biennial from a taproot; flowers white, never yellow CARUM CARVI L . 13 Plants perennial, with or without a taproot; native species, not weedy 14 Fruit armed with hooked prickles SANICULA GRAVEOLENS Poepp 14 Fruit unarmed 161 15 Plants definitely taprooted, the taproot sometimes fleshy - thickened, but distinctly elongate; taproot often sur- mounted by a stout branching caudex 16 Fruit essentially wingless, slightly compressed laterally MUSINEON DIVARICATUM (Pursh) Nutt. 16 Fruit with at least the lateral ribs produced into evident wing-margins when fully mature 17 Body of the fruit subterete or slightly compressed laterally LIGUSTICUM 17 Body of the fruit distinctly compressed dorsally 18 Dorsal ribs of the fruit wingless or nearly so, only the lateral ribs distinctly winged; involucel dimidiate or not LOMATIUM 18 Dorsal ribs of the fruit generally winged, the wings sometimes narrower than those of the lateral ribs; involucel dimiditate (all on one side of the umbellet) CYMOPTERUS 15 Plants with fibrous or fleshy-thickened roots; roots when flesh-thickened either clustered or solitary, and when solitary always short, not over about an inch long 19 Roots strictly fibrous, not at all fleshy; plants growing in water or very wet places BERULA ERECTA (Huds.) Cov 19 Roots or some of them more or less fleshy-thickened; plants of wet or more often dry places 20 Fruit slightly to strongly flattened laterally, wingless or the mericarps with thickened, incurved lateral wings; flowers white or pink 21 Fruit linear, mostly 8-10 mm long LOMATIUM 21 Fruit linear-oblong or broader, 2-7 mm long PERIDERIDIA GAIRDNERI (H. & A.) Mathais 20 Fruit more or less strongly flattened dorsally, the marginal ribs with thin spreading wings at maturity; flowers yellow or white LOMATIUM 162 Angelica L. 1 Leaves oblong to elliptic, pinnate to incompletely bipin- nate; involucel wanting A . PINNATA Wats. 1 Leaves more deltoid, ternate-pinnate; involucel present or absent A . ARGUTA Nutt . Cymopterus Raf. (Including Pteryxia & Pseudocymopterus) 1 Calyx teeth prominent, linear-lanceolate, acuminate C. TEREBINTHINUS (Hook.) T.& G. 1 Calyx teeth minute or lacking C. LONGIPES (S.Wats.) C.&R. Ligusticum L. Licorice-root 1 Leaves dissected into numerous more or less linear seg- ments mostly 1-3 mm wide L. FILICIN.UM Wats. 1 Leaves less dissected, the ultimate segments broader 2 Secondary leaflets divided nearly to midrib L. PORTER Coult.&Rose 2 Secondary leaflets not divided nearly to midrib (presence of this taxon in the park is questionable. Our only specimens with this name are immature) L. CANBYI Coult.& Rose Lomatium Raf. Desert Parsley; Biscuitroot 1 Ultimate segments of the leaves relatively large, many or all of them 1 cm long or longer 2 Ultimate segments of the leaves forming more or less definite leaflets, these entire to deeply cleft, usually over 5 mm wide 3 Herbage (or at least the stems and peduncles) more or less hirtellous puberulent L. TRITERNATUM (Pursh) Coult. & Rose 3 Herbage essentially glabrous and often glaucous L. NUDICAULE (Pursh) Coult. & Rose 163 2 Ultimate segments of the leaves narrow and scarcely leafletlike, seldom as much as 5 mm wide 4 Fruits linear to narrowly oblong, mostly (2.5) 3-8 times as long as wide, less than 4 mm wide over-all the wings up to 1/3 or rarely 1/2 as wide as the body, or obsolete 5 Involucel generally wanting; pedicels elongate, mostly 4-13 mm long at maturity; flowers yellow or somewhat purplish in age L. AMBIGUUM (Nutt . ) Coult . & Rose 5 Involucel present; pedicels short or elongate; flowers yellow or white L. TRITERNATUM (Pursh) Coult. & Rose 4 Fruits broader, either more than 4 mm wide, or not more than about 2.5 times as long as wide, the wings often well over 1/3 as wide as the body 6 Bractlets of the involucel broadly oblanceolate to broadly obovate or elliptic; flowers yellow L. COUS (Wats.) Coult. & Rose 6 Bractlets of the involucel narrow, mostly linear or lanceolate, or wanting 7 Stems or scapes solitary or few from the simple or occasionally few-branched rootcrown L. TRITERNATUM (Pursh) Coult . & Rose 7 Stems several or numerous from a large, woody root that is often surmounted by a branching caudex L. DISSECTUM (Nutt.) Math. & Const. Ultimate segments of the leaves relatively small, rarely any of them as much as 1 cm long 8 Bractlets of the involucel broadly oblanceolate to obovate, ovate, or subrotund, entire to sometimes more or less connate L. COUS (Wats.) Coult. &Rose 8 Bractlets of the involucel narrow, mostly linear or lanceolate, distinct or merely connate at the base, or wholly wanting L. MACROCARPUM (Nutt.) Coult. & Rose 164 Osmorhiza Raf. Sweet Cicely 1 Fruit concavely narrowed to the summit, the terminal (0. 5) 1-2 mm more or less distinctly set off as a broadly beaklike apex; pedicels and rays of the umbel mostly ascending-spreading O . CHILENSIS H.&A. 1 Fruit convexly narrowed to the rounded or obtuse to merely acutish summit, the apex not at all beaklike; pedicels and rays of the umbel generally widely divar- icate O. DEPAUPERATA Phil. CORNACEAE Dogwood Family Cornus L. Dogwood 1 Low trailing subshrub less than 3 dm tall, the leaves whorled at the tip of the stem C. CANDENSIS L. 1 Woody trees or shrubs with opposite leaves throughout C . STOLONIFERA Michx . ERICACEAE Heath Family 1 Plants without green leaves 2 Corolla urn-shaped, gamopetalous; anthers awned on the back PTEROSPORA ANDROMEDEA Nutt. 2 Corolla not urn-shaped, usually polypetalous; anthers unawned HYPOPITYS MONOTROPA Crantz 1 Plants with well-developed, green leaves 3 Ovary inferior or apparently inferior because of the fleshiness of the persistent calyx; fruit a true berry or a capsule surrounded by the thickened, fleshy calyx which forms a pseudo berry 4 Ovary truly inferior; erect shrubs, mostly deciduous VACCINIUM 4 Ovary superior but surrounded by the fleshy calyx when ripe and apparently inferior; mostly prostrate to semierect evergreen shrublets GAULTHERIA HUMIFUSA (Grah.) Rydb. 3 Ovary superior, free of the calyx 165 Fruit fleshy; creeping evergreen shrub with relatively- larger, leathery leaves and deep reddish to purplish bark; flowers urn-shaped ARCTOSTAPHYLOS UVA-URSI (L . ) Spreng . Fruit a dry capsule; herbs to large shrubs; corolla often not urn- shaped; leaves often scalelike 6 Corolla polypetalous or nearly so, flowers usually open and not at all tubular 7 Plants more herbaceous than woody, seldom over 3 dm tall; leaves large and coriaceous, evergreen 8 Leaves cauline, scattered or whorled, the plants scapose; styles very short, usually not noticeable; filaments enlarged and hairy about midlength; flowers corymbose CHIMAPHILA UMBELLATA (L.) Bart. 8 Leaves mostly basal, the plants scapose; styles elongate, visible in flower, often strongly curved; filaments not enlarged and hairy; flowers racemose or single PYROLA 7 Plants woody shrubs, usually over 3 dm tall LEDUM GLANDULOSUM Nutt . 6 Corolla gamopetalous; flowers often urceolate 9 Corolla rotate (saucerlike) with 10 pouches in which the anthers fit in the bud; leaves often strongly revolute KALMIA MICROPHYLLA Heller 9 Corolla either not rotate or not saccate PHYLLODOCE EMPETRIFORMIS (Sw.) D.Don Pyrolla L . Pyrola; Shinleaf; Wintergreen 1 Flowers single and terminal (Moneses) P . UNIFLORA L . 1 Flowers two or more in racemes 2 Style straight or nearly so, without a collar or ring below the peltate-lobed stigma; flowers less than 1 cm broad; anthers opening at the upper end by large pores and without either horns or tubes pro- jecting above the pores 3 Styles usually well over 2 mm long; racemes secund petals white, 4-5 mm long (Ramischia) P. SECUNDA L. 166 3 Styles not over 2 mm long; racemes not secund; petals flesh color or pinkish, about 3 mm long (Erxlebenia) P. MINOR L. 2 Style bent to one side, often with a collar or ring below the stigma; flowers usually at least 1 cm broad; anthers usually with short horns or tubes and lateral pores (Pyrola) 4 Leaves deep green but mottled on the upper surface with pale streaks above the main veins; blades mostly ovate to ovate-elliptic P . PICTA Smith 4 Leaves not mottled; blades various 5 Leaves tapered to an acute base, spatulate or oblanc- eolate to rhombic-elliptic, usually at least 3 cm long and not much over 1/2 as broad, seldom over 2. 5 cm in width, pale green or bluish-green, thickish; petals greenish-white; racemes 10- to 30-flowered P. DENTATA Smith 5 Leaves usually ovate to orbicular and well over half as long as broad, many over 2.5 cm in width, often rounded at the base 6 Flowers pale yellowish or greenish-white (P. virens) P. CLORANTHA Sw. 6 Flowers pinkish to rose-purple P. ASARIFOLIA Michx. Vaccinium L . Blueberry; Huckleberry; Whortleberry 1 Branches bright green or yellow-green, sharply angled, very numerous; leaves sharply serrulate, usually less than 15 mm long; berry bright, but not deep, red; pedicels less than 3 mm long; flowers about 4 mm long; plants usually less than 2.5 dm tall V . SCOPARIUM Leiberg 1 Branches usually neither bright green nor sharply angled, but if angled then the leaves mostly over 15 mm long, or the berry not red or plants over 2 . 5 dm tall 2 Plants usually 2-3 dm tall; berry dark red to bluish; branches green and angled; leaves sharply serrulate, 1-3 cm long; flowers single in the axils V . MYRTILLUS L . 2 Plants either over 4 dm tall or branches not angled, or leaves entire or but slightly serrulate; flowers often more than 1 per axil; berry mostly deep bluish-black 167 3 Calyx deeply lobed, the lobes triangular, persistent in fruit; flowers 1-4 per axil; buds with 4-7 scales, these conspicuous at the base of the pedicels; branches not angled; leaves entire V. OCCIDENTALE Gray 3 Calyx shallowly lobed, the rounded lobes deciduous; tube of calyx forming a crowning ring on the fruit; branches often angled; flowers single in the leaf axils; bud scales two 4 Plants usually 2-3 (less than 5) dm tall; leaves more or less serrate above the middle, mostly no more than indistinctly serrulate on the lower half; twigs incon- spicuously angled to terete V. CAESPITOSUM Michx. 4 Plants either well over 5 dm tall, or the leaves either entire or serrulate below midlength V. GLOBULARE Rydb . PRIMULACEAE Primrose Family 1 Plant a caespitose perennial with cushions of persistent, small, narrow leaves; flowering stems leafless, flowers 1-several, showy, pink to violet DOUGLASIA MONTANA Gray 1 Plants not caespitose, or if so, the corollas white or the stems leafy 2 Leaves in basal rosettes; flowering stems leafless 3 Lobes of the corolla several times as long as the tube, sharply reflexed; stamens protruding their full length DODECATHEON Merrill 3 Lobes of the corolla less than twice as long as the tube, not sharply reflexed; stamens usually included ANDROSACE 2 Leaves not confined to basal rosettes; flowering stems leaf-bearing GLAUX MARITIMA L. Androsace L. 1 Perennial, grayish-pilose; scapes single from each rosette; corolla lobes over 2 mm long A. LEHMANNIANA Spreng . 1 Annuals or biennials, not pilose; scapes usually several from the leaf rosette 168 2 Flowers less than 3 mm long; calyx hemisperic; plant glabrous or sparsely glandular-puberulent above; leaves abruptly narrowed to distinct petioles; seeds light yellow, less than 0.5 mm long A. FILIFORMIS Rete. 2 Flowers often more than 3 mm long; calyx more nearly turbinate; plants usually puberulent; leaves narrowed gradually to the base; seeds dark brown, over 0. 5 mm long A. SEPTENTRIONALIS L. Dodecatheon L. Shooting Star 1 Filaments usually less than 1 (1.5) mm long, free or united into a tube, the connectives cross-wrinkled; capsule operculate D . CONJUGENS Greene 1 Filaments usually over 1.5 mm long, connectives often smooth or longitudinally wrinkled rather than cross-wrinkled; capsule valvate to the tip D. PULCHELLUM (Raf.) Merrill GENTIANACEAE Gentian Family 1 Corolla salverform to tubular, the lobes usually no longer than the tube GENTIANA 1 Corolla rotate, the lobes usually longer than the tube 2 Styles thick, scarcely 1 mm long; flowers 5-merous SWERTIA PERENNIS L . 2 Styles slender, at least 2 mm long; flowers 4-merous FRASERA SPECIOSA Dougl. Gentiana L . Gentian 1 Perennials; corollas usually 5-merous and well over 2.5 cm long, if shorter then the plants either somewhat prostrate and matted and spreading by very slender rhizomes, or the leaves with long, sheathing, connate bases and the blades then less than 1 cm long; stigmas never flabellate-erose 2 Flowers white or pale yellowish, blotched and striped with purple; leaves 4-12 cm long, usually three times as long as broad G. ALGIDA Pall. 169 2 Flowers bluish or purple, if yellowish then the leaves scarcely 2 times as long as broad G. AFFINIS Griseb. 1 Annuals; corollas mostly less than 2 cm long, if longer, then usually 4-merous or with lacerate-fimbriate lobes, or the stigmas broadly flabellate-erose 3 Corollas deep blue, usually over 2 cm long, 4-merous; stigmas broadly flabellate-erose G. DETONSA Rottb . 3 Corollas less than 2 cm long and not deep blue, some- times 5-merous; stigmas not flabellate-erose G. AMARELLA L. APOCYNACEAE Dogbane Family Apocynum L. Dogbane 1 Flowers less than 5 (2-4.5) mm long; corolla greenish- white to white, usually less than twice as long as the calyx, lobes erect or but slightly spreading; leaves ascending 2 Follicles usually more than 12 cm long; coma of seeds 2-3 cm long; leaves, except sometimes the lower cauline, distinctly petioled and not cordate-based A. CANNABINUM L. 2 Follicles less than 12 cm long; coma of seeds 1-2 cm long; leaves of main stem usually all sessile or sub- sessile and cordate-based A. SIBIRICUM Jacq. 1 Flowers usually at least 5 mm long; corolla pinkish, often more than twice the length of the calyx, the lobes spreading to reflexed; leaves mostly drooping to spreading 3 Calyx usually at least half as long as the corolla, the lobes narrowly lanceolate, acute to acuminate; leaves often ascending A . MEDIUM Greene 3 Calyx usually less than half as long as the corolla, the lobes lanceolate to deltoid or ovate often obtuse; leaves mostly spreading or drooping A. ANDROSAEMIFOLIUM L. 170 POLEMONIACEAE Phlox Family 1 Leaves represented only by the persistent cotyledons and by a whorl of entire, often basally connate bracts just beneath the compact inflorescence; small annuals GYMNOSTERIS PARVULA Heller 1 Leaves more or less well developed, either clustered at the base, or distributed along the stem, or both; annual to perennial 2 Calyx tube of essentially uniform texture throughout, somewhat accrescent, not ruptured by the developing capsule; leaves not at once palmatifid and sessile 3 Leaves pinnately compound, with definite leaflets (these broader than linear except in one species); calyx tube herbaceous at anthesis; perennials, one species annual POLEMONIUM 3 Leaves entire to variously dissected, but without definite leaflets; calyx tube chartaceous at anthesis COLLOMIA LINEARIS Nutt. 2 Calyx tube with green costae separated by hyaline intervals, or, if greenish essentially throughout, then the leaves sessile and palmatifid into linear segments 4 Filaments very unequally inserted; leaves entire, partly or wholly opposite 5 Perennial; leaves all, or nearly all, opposite; seeds not becoming mucilaginous when moistened PHLOX 5 Annual; upper leaves alternate; seeds becoming mucilaginous when moistened MICROSTERIS GRACILIS (Hook . ) Greene 4 Filaments about equally, or occasionally somewhat unequally, inserted; leaves seldom at once opposite and entire 6 Leaves sessile, palmatifid into linear segments 7 Annual; leaves soft, mostly or all opposite; seeds often becoming mucilaginous when moistened LINANTHUS SEPTENTRIONALIS Mason 7 Perennial; seeds remaining unchanged when moistened LEPTODACTYLON PUNGENS (Torr.) Nutt. 6 Leaves diverse, but not at once sessile and pal- matifid; herbs or subshrubs with alternate (or all basal) , entire to dissected leaves GILIA 171 Gilia R.& P. 1 Corolla relatively very large (the undivided portion 1.5- 3.5 cm long), often partly or wholly bright red; biennial or short-lived perennial G. AGGREGATA (Pursh) Spreng. 1 Corolla smaller (the undivided portion not over 1 cm long) , never bright red G . TENERRIMA Gray Phlox L. Wild Sweet William 1 Plants more or less erect, or loosely repent, with well- developed internodes, and with the larger leaves often more than 3 . 5 cm long or more than 5 mm wide; flowers mostly slender-pedicellate in a 3- to many-flowered terminal cyme P . LONGIFOLIA Nutt. 1 Plants compact and tending to form mats, occasionally looser and up to 1 or even 1.5 dm tall; leaves short and crowded, rarely more than 3 cm long, never more than 5 mm wide; flowers mostly solitary (3), short -pedicellate or sessile at the ends of the numerous stems, scarcely forming distinct inflorescences 2 Leaves narrowly linear, mostly (2.5) 4-10 (13) mm long and about 0.5 (1) mm wide near the middle, firm and pungent, very often arachnoid; plants forming dense cushions; style 2-5 (6) mm long P. HOODII App. 2 Leaves never arachnoid, and usually longer or wider, or distinctly softer than those of P. hoodii, but if similar to those of P . hoodii in size and texture, then the plants looser and suberect 3 Plants tending to be loosely erect, 5-15 cm tall, often resembling a small Leptodactylon in habit; leaves narrow, firm, commonly 5-13 mm long and 0.5 (1) mm wide near the middle; calyx and pedicels (often also the herbage) usually glandular; style 3-7 (8) mm long; chiefly in and near the lower douglas-fir zone P. CAESPITOSA Nutt. 3 Plants either more compactand mat-forming, or, if looser and suberect, then with the leaves distinctly longer, or wider, or softer than those of P. caespitosa; pubescence and styles diverse 172 4 Styles 1-5 mm long; leaves fairly firm, rarely as much as 1.5 cm long, the margins somewhat thickened, but not strongly whitish; calyx usually glandular-hairy; moderate to high elevations in the mountains P. PULVINATA (Wherry) Cronq. 4 Styles mostly 5-12 mm long, or occasionally only 4 mm in plants which differ in other respects from P. Pulvinata P. MULTIFLORA A.Nels. Polemonium L. 1 Corolla more or less funnelform or tubular-funnelform to subsalverform , longer than wide, the lobes shorter than the tube; dwarf (rarely to 4 dm) alpine and sub- alpine, petrophilous , very strongly glandular and mephitic plants with numerous stems from a taproot and much-branched (sometimes elongate) caudex P. VISCOSUM Nutt. 1 Corolla campanulate or broader, about as wide as long, or wider, the lobes about as long as the tube, or longer; plants of various habit, usually less strongly glandular and mephitic 2 Stems solitary from the upturned end of a mostly rather short and simple horizontal rhizome, erect, (1. 5) 4-10 dm tall; very wet places at moderate elevations P. OCCIDENT ALE Greene 2 Stems more or less clustered from a branched (some- times elongate and rhizome-like) caudex which usually surmounts a taproot; plants lax, up to 3 (5) dm tall, of moist to dry, often rocky places, at moderate to high elevations P . PULCHERRIMUM Hook. 173 HYDROPHYLLACEAE Waterleaf Family 1 Flowers (at least in our species) borne singly, or some- times a few of them in a lax, few-flowered, terminal inflorescence 2 Leaves entire or subentire; placentae more or less strongly intruded and partitionlike HESPEROCHIRON PUMILUS (Griseb . ) Porter 2 Leaves coarsely toothed to pinnatifid; placentae enlar- ged but not at all partitionlike, nearly filling the young ovary, and forming a lining for the mature capsule NEMOPHILA BREVIFLORA Gray 1 Flowers in definite inflorescences, not solitary 3 Inflorescence of subdichotomously branched (some- times capitate) cymes without an evident central axis; placentae enlarged but not at all partitionlike, nearly filling the young ovary, and forming a lining for the mature capsule; fibrous-rooted, perennial mesophytes with cleft leaves and exserted stamens HYDROPHYLLUM CAPITATUM Dougl . 3 Inflorescence of one or more sympodial, more or less helicoid cymes which may be aggregated into a compound, often thyrsoid inflorescence; placentae evidently intruded and partitionlike; taprooted annuals or perennials, mesophytic or xerohytic, with entire to variously dissected leaves and included or exserted stamens PHACELIA Phacelia Juss. 1 Leaves all entire, or in some species some of them with a large, entire terminal segment and one or several smaller, entire lobes or leaflets below the middle 2 Plants biennial or perennial; filaments strongly exserted; ovules 4; seeds 1-4 P. HASTATA Dougl. 2 Plants annual; filaments only shortly or not at all exserted; ovules (and usually seeds) more than 4 P. LINEARIS (Pursh) Holz. 174 1 Leaves coarsely toothed or pinnatilobate to more often pinnatifid or bipinnatifid, mostly without a large, entire, terminal segment 3 Plants annual or biennial, single-stemmed or with central stem surrounded by ascending lesser stems; corolla glabrous within; filaments only shortly or scarcely exserted P. FRANKLINII (R.Br.) Gray 3 Plants perennial, usually several-stemmed; corolla hairy within P. SERICEA (Grah.) Gray BORAGINACEAE Borage Family 1 Nutlets broadly attached at the base to the broad low gynobase LITHOSPERMUM 1 Nutlets apically or medially to basilaterally or nearly basally attached, but the attachment, if nearly basal, always small 2 Nutlets either evidently armed with glochidiate prickles or uncinate bristles , or provided with a continuous, entire or cleft dorsomarginal ridge or wing that is complete around the base or across the back of the nutlet, or both armed and ridged 3 Nutlets more or less widely spreading in fruit, the rather large scar apical or apicolateral , not extending below the middle of the fruit, never elongate and narrow CYNOGLOSSUM OFFICINALE L . 3 Nutlets erect or incurved to somewhat spreading; scar distinctly otherwise 4 Nutlets essentially unarmed, the dorsomarginal ridge entire or merely toothed lacerate MYOSOTIS SYLVATICA Hoffm . 4 Nutlets armed with glochidiate prickles at least along the dorsomarginal ridge 5 Nutlets narrowly attached to the elongate gynobase along the well-developed, median, ventral keel, free near the base; pedicels erect or ascending in fruit; "racemes" evidently bracteate; plants mostly annual LAPPULA REDOWSKII (Hornem . ) Greene 175 5 Nutlets medially attached to the broad, low gynobase, the scar more or less rounded, not elongate; pedicels recurved or deflexed in fruit; "racemes" naked or nearly so; plants mostly perennial HACKELIA 2 Nutlets smooth or variouly roughened, but without hooked or glochidiate prickles or bristles (except for some very small dorsal ones in species of Plagiobothrys) , sometimes sharp-edged, especially distally, but not with the ridge complete across the back or around the base of the nutlet 6 Corolla blue or occasionally pink (in rare individuals white), tubular or tubular-funnelform to campanulate, never salverform; perennials, never pungently hairy MERTENSIA 6 Corolla white to yellow or orange, often salverform; annual or perennial, often pungently hairy 7 Nutlets with a closed or narrowly open ventral groove-scar running most of their length, this often expanded below into a depressed areola; plants annual to perennial, often pungently hairy CRYPTANTHA 7 Nutlets with a ventral keel extending to the middle or to near the base, the attachment elevated, caruncle- like, placed at the base of the keel, or rarely extend- ing along the keel; ours annuals and generally not pungently hairy PLAGIOBOTHRYS SCOULERI (H.&A.) Johnst. Cryptantha Lehm ■ 1 Plants perennial or sometimes merely biennial, relatively coarse, usually with a well-developed tuft of basal leaves; spikes aggregated into a dense, terminal, irregularly bracteate thyrse, often eventually elongating and distinct; corolla more or less conspicuous, the limb mostly 4-12 mm wide; calyx persistent C. INTERRUPTA (Greene)Pays . 1 Plants annual, relatively slender, without any conspicuous tuft of basal leaves; corollas not over about 2.5 mm wide 2 Nutlets all smooth, or finely and inconspicuously gran- ular, not at all tuberculate or spiculate-papillate 176 3 Nutlets of 2 kinds, 1 differing definitely in size, color, or shape from the others C. PATTERSONII (Gray)Greene 3 Nutlets all alike or esentially so (sometimes 1 or more fails to develop) 4 Margins of the nutlets prominent, sharply angled, especially above C. WATSONII (Gray)Greene 4 Margins of the nutlets rounded or obtuse, not prom- inent 5 Nutlets lanceolate, 0 . 5-0 . 7 mm wide; plants of very sandy soil C. FENDLERI (Gray)Greene 5 Nutlets ovate, 0.8-1.2 mm wide; plants common and widespread in our area C. TORREYANA (Gray)Greene 2 Nutlets, or some of them, rough, with evident tubercles or spiculate papillae on the dorsal surface C . AMBIGUA (Gray) Greene Hackelia Opiz. Stickseed; Wild Forget-me-not 1 Corolla limb blue, sometimes withering pink 2 Plants relatively short lived, biennial or barely perennial, often single-stemmed from a taproot and simple crown; intramarginal prickles wanting, or occasionally 1 or 2 H. FLORIBUNDA (Lehm . ) Johnst . 2 Plants perennial, ordinarily with several or many stems from a taproot and branching caudex; intramarginal prickles present, usually several H. MICRANTHA (Eastw . ) J . L .Gentry 1 Corolla limb white to ochroleucous or greenish-tinted, sometimes marked or very lightly washed with pale blue H . PATENS (Nutt . ) Johnst . Lithospermum L. Stoneseed 1 Corolla pale yellowish, often greenish-tinted, the tube 4-6 mm long, the limb 7-13 mm wide, the lobes entire or nearly so L . RUDERALE Dougl . 1 Corolla bright yellow, the tube (12) 15-30 mm long, the limb 10-20 mm wide, the lobes evidently erose L . INCISUM Lehm . 177 Mertensia Roth Nom . Conserv. Bluebells 1 Plants relatively tall and robust (4-15 dm) with evident lateral veins in cauline leaves; blooming in late spring and summer M . CILIATA (Torr.)G.Don 1 Plants smaller, seldom as much as 4 dm tall, usually without evident lateral veins (except sometimes in M. oblongifolia, which can also be up to 6 dm tall but is separated by its longer lanceolate calyx teeth) blooming as soon as snow and temperature permit 2 Filaments short scarcely if at all over 1 mm long, base of anthers not elevated beyond the fornices of the corolla, alpine plants M. ALPINA (Torr . ) G.Don 2 Filaments longer and more conspicuous, broad and flattened, 1.5-3 mm long; base of anthers elevated above the fornices; plants not alpine, except sometimes M . viridis 3 Corolla tube bearing a ring of hairs inside below the middle (sometimes scattered over much of the inner surface) tube usually shorter than limb; moder- ate to high elevations M . VIRIDIS A.Nels. 3 Corolla tube glabrous inside, obviously longer than the limb; foothills to moderate elevations M. OBLONGIFOLIA (Nutt.) G. Don LABIATAE Mint Family 1 Corolla only obscurely or scarcely bilabiate, either subequally 5-lobed with the lobes all about alike, or subequally 4-lobed with one of the lobes usually broader than the others and sometimes emarginate 2 Stamens 4; plants aromatic; calyx 10-nerved; corolla white , pink or purple MENTHA ARVENSIS L . 2 Stamens 2; plants odorless; calyx 5-nerved; corolla white LYCOPUS AMERICANUS Muhl . 1 Corolla more or less strongly bilabiate 3 Stamens 2 MONARDA FISTULOSA L . 3 Stamens 4 (or obsolete in pistillate plants) 4 Calyx bilabiate, with entire lips, bearing a prominent transverse external appendage on the upper side; lower stamens each with only 1 functional pollen sac SCUTELLARIA GALERICULATA L . 178 4 Calyx regular or irregular, sometimes bilabiate, but in every case evidently toothed, and lacking any transverse appendage; each stamen with 2 pollen sacs, these some- times confluent in dehiscence 5 Inflorescnece appearing terminal, the verticels tending to be crowded and mostly subtended by mere bracts that are evidently differentiated from the foliage leaves 6 Stamens evidently exserted, readily visible without dissection of the flower; upper lip of the corolla not at all galeate AGASTACHE UTRICIFOLIA (Benth. ) Kuntze 6 Stamens ascending under the more or less galeately rounded upper lip of the corolla, scarcely or not at all exserted 7 Calyx 5- to 10-nerved; lower stamens longer than the upper PRUNELLA VULGARIS L . 7 Calyx 15-nerved; upper stamens longer than the lower 8 Calyx regular or nearly so, with subequal teeth NEPETA CATARIA L . 8 Calyx strongly irregular, ours with the upper tooth much broader than the other 4 DRACOCEPHALUM PARVIFLORA Nutt. 5 Inflorescences appearing axillary, the flowers or vert- icels of flowers mostly subtended by more or less well developed leaves that are separated (except often in Lamium) by internodes of approximately normal length 9 Lower lip of the corolla constricted at the base of the enlarged, cleft or emarginate central lobe, the lateral lobes broad and low, seeming to arise from the corolla throat, each terminating in a short, divergent tooth LAMIUM AMPLEXICAULE L . 9 Lower lip of the corolla not constricted at the base of the central lobe, the lateral lobes directed more or less forward 10 Lower lip of the corolla with a pair of nipples pro- jecting internally near the base; annual GALEOPSIS LADANUM L . 10 Lower lip of the corolla without nipples; our specie perennial GLECOMA HEDERACEA L . 179 SOLANACEAE Potato or Nightshade Family 1 Fruit capsular, dehiscent; flowers relatively large, the corolla funnelform to salverform, in ours 2-10 cm long; heavy-scented, narcotic herbs, ours annual or biennial HYOSCYAMUS NIGER L . 1 Fruit a fleshy or dry berry, indehiscent; flowers smaller, ours less than 2 cm long, funnelform or campanulate to rotate, or with reflexed lobes; plants of diverse habit, ours not markedly heavy-scented SOLANUM Solanum L . Nightshade 1 Leaves evidently pinnatilobate S. TRIFLORUM Nutt . 1 Leaves entire to merely toothed or wavy-margined S. SARRACHOIDES Sendt. SCROPHULARIACEAE Figwort Family 1 Corolla galeate, i.e. the upper lip forming a hood or beak (galea) that tends to enclose the anthers, the teeth of the upper lip short or obsolete; inflorescence of leafy- bracted spikes, spikelike racemes, or heads; stigmas wholly united; sepals more or less connate at least below (some- times in groups) 2 Pollen sacs similar in size and position; calyx lobes typically 5, sometimes 4 or only 2; leaves toothed to dissected, never entire, often basal as well as cauline PEDICULARIS 2 Pollen sacs unequally set, one medifixed and appearing terminal on the filament, the other (sometimes reduced or obsolete) attached by its apex and pendulous or lying alongside the upper part of the filament; calyx lobes 2-4; leaves wholly cauline, entire or cleft, seldom toothed or definintely pinnatifid with broad segments 3 Galea more or less strongly surpassing the lower lip; plants perennial, except for C. exilis, in which the galea is very conspicuously longer than the lower lip CASTILLEJA 3 Galea only slightly, or not at all, surpassing the lower lip; plants annual ORTHOCARPUS LUTEUS Nutt. 180 1 Corolla not galeate, though often bilabiate, the upper lip if differentiated, not forming a hood or beak; inflores- cences, sepals and stigmas diverse 4 Filaments 5; stigmas wholly united 5 Anthers 5; leaves alternate; corolla rotate, only slightly irregular VERBASCUM THAPSUS L. 5 Anthers 4; leaves opposite (the cauline ones some- times much reduced); corolla tubular, more or less strongly bilabiate PENSTEMON 4 Filaments 2-4 6 Anthers 2; sepals distinct, except in Besseya 7 Leaves wholly cauline, opposite (the bracts some- times leafy and alternate) VERONICA 7 Leaves chiefly basal, the cauline ones, if present, reduced, usually alternate; stigmas wholly united BESSEYA WYOMINGENSIS (A.Nels.) Rydb. 6 Anthers 4; sepals diverse 8 Flowers with the central lobe of the lower lip keeled-saccate, forming a pouch which encloses the stamens; annuals COLLINSIA PARVIFLORA Lindl . 8 Flowers with the central lobe of the lower lip flat or nearly so, not forming a pouch; annuals or perennials MIMULUS Castilleja Mutis Indian Paintbrush 1 Root annual; stems usually solitary; leaves and bracts entire, linear-lanceolate, the latter much longer than the flowers, with only distal 1/3 of the uppermost colored red C . EXILIS A.Nels. 1 Root perennial, usually woody; stems clustered, often decumbent and sometimes rooting at the base; bracts 3- to 9-lobed or -divided or, if entire, much broader 2 Galea short, rarely over 1/2 the length of the corolla tube; lower lip prominent, usually more than 1/3 the length of the galea; bracts usually yellow or yellowish, rarely purplish or reddish, except C . pulchella 3 Calyx subequally cleft into 4 linear or triangular lobes C. LONGISPICA A.Nels. 181 3 Calyx divided usually less than half as deeply laterally as sagittally 4 Calyx lobes acute or, if obtuse or obtusish, the plants rather harshly puberulent or pubescent or growing in dry habitats C. PALLESCENS (Gray) Greenm. 4 Calyx lobes obtuse or, if acute, the plants rather softly pubescent and growing in meadows or other moist situations 5 Bracts mostly as long as, or longer than, the flowers, obtuse or rounded; plants mostly of medium and lower elevations C. CUSICKII Greenm. 5 Bracts mostly shorter than the flowers, at least the lower ones acute or acutish, purple or purplish; plants of alpine and subalpine habitats C. PULCHELLA Rydb . 2 Galea usually longer and more slender, at times equaling or exceeding corolla tube length; lower lip usually reduced, dark green and thickened, in most species 1/5 galea length or less (more prominent and as much as 1/3 galea length in C rhexifolia ad C. sulphur ea); bracts showy, red or purple, rarely yellowish or whitish except in C . gracillima and C . sulphurea 6 Calyx much more deeply cleft below than above, usually more showy than the bracts C. LINARIAEFOLIA Benth. 6 Calyx subequally cleft above and below or more deeply so above; bracts usually more showy than the calyx 7 Bracts predominantly yellow or yellowish (but varying to red or purple C. gracillima) 8 Stems clumped, rather stout, erect or ascending from a woody base C . SULPHUREA Rydb. 8 Stems mostly solitary, although several may be attached to a remote caudex, slender, decumbent or creeping and often rooting at the base; wet meadows, middle altitudes C. GRACILLIMA Rydb. 7 Bracts predominantly red or purple, yellow only in rare individuals 9 Stems mostly 1-3 dm tall, usually unbranched; bracts crimson (drying purple) , rarely scarlet; flowers mostly 20-30 mm long; alpine and sub- alpine zones C. RHEXIFOLIA Rydb. 182 9 Stems mostly more than 3 dm tall, often branched; bracts scarlet, rarely crimson; flowers mostly 30-40 mm long; plants of lower elevations C . MINIATA Dougl . Linaria Mill . Toadflax 1 Leaves linear, not clasping L . VULGARIS Hill 1 Leaves ovate or lance-ovate, clasping L. DALMATICA (L . ) Mill. Mimulus L . Monkey Flower 1 Plants perennial from rhizomes or stolons; flowers long- pedicellate, the pedicels longer than the calyx; corollas dropping before withering; septum of the capsule remain- ing intact at maturity, or splitting only above the middle 2 Corollas pink-purple, marked with yellow, 3-5.5 cm long; calyx 1.5-2.5 (3) cm long; erect plants with the leaves sessile and several-nerved from the base M. LEWISII Pursh 2 Corollas yellow, sometimes marked with red or maroon, or in part washed with pale purplish; calyx, habit, and habitat diverse 3 Upper calyx toothed conspicuously larger than the others; leaves palmately or subpalmately veined, the 3-7 main veins arising at or very near the base; corolla strongly bilabiate, and with broad, strongly flaring throat 4 Plants with definite, creeping, often sod-forming rhizomes, often stoloniferous as well; flowers few (mostly 1-5), large, the corolla mostly 2-4 cm long; low plants, commonly 2 dm tall or less, of high altitudes in the mountains M. TILINGII Regel 4 Plants with stolons, but only rarely with definite creeping rhizomes; flowers often more than 5, and usually less than 2 cm long when few; plants usually over 2 dm tall; low to moderate elevations in the mountains M. GUTTATUS DC. 183 3 Upper calyx tooth not evidently larger than the others, or if so, then the leaves pinnately veined; corolla various M. MOSCHATUS Dougl. 1 Plants annual, without stolons or rhizomes; pedicels, corollas, and capsules diverse 5 Corollas yellow, often marked with red or maroon; pedicels elongate, mostly longer than the calyx; corollas generally diciduous before withering; septum of the capsule remaining intact at maturity, or splitting only above the middle 6 Corolla strongly bilabiate, the lower lip evidently longer than the upper and strongly deflexed from it; corolla not less than 8 mm long; principal leaves of fairly broad form and usually petiolate M . GUTTATUS DC. 6 Corolla only slightly bilabiate, the lower lip only slightly longer than the upper and not much deflexed from it; corolla often less than 8 mm long; leaves diverse 7 Leaves abruptly contracted to the petiole; herbage generally evidently viscid-pubescent, or some- times only shortly and inconspicuously so M . FLORIBUNDUS Lindl . 7 Leaves tapered to the petiolar or sessile base; herbage finely glandular-puberulent M . SUKSDORFII Gray 5 Corollas purple or red commonly marked in the tube or throat with yellow or white; pedicels, except often in M. breweri, mostly shorter than the calyx; corollas tending to persisit for sometimes after withering (the tendency least marked in M. breweri) 8 Flowers small and slender, 5-10 mm long; septum splitting only above the middle; pedicels from a little shorter to evidently longer than the calyx M . BREWERI (Greene) Rydb . 8 Flowers larger and more showy, 1-5 cm long; septum splitting to the base at maturity, the halves of the placenta adherent to the respective valves; pedicels shorter than the calyx M. NANUS H. & A. 184 Pedicularis L . Lousewort 1 Leaves merely toothed; calyx lobes 2 P. RACEMOSA Dougl. 1 Leaves or many of them pinnatilobate to bipinnatifid; calyx lobes 5 2 Plants leafy-stemmed, the basal leaves, if present, not markedly larger than the cauline (though sometimes with longer petioles); bracts sharply differentiated from the leaves; galea beakless or with a very short beak P. BRACTEOSA Benth. 2 Plants with the leaves basally disposed, the cauline leaves mostly few and more or less reduced 3 Pinnae of the leaves, or many of them, deeply cleft P. CYSTOPTERIDIFOLIA Rydb . 3 Pinnae or lobes of the leaves mostly merely toothed 4 Beak straight, spreading, about 1-4 mm long P. PARRYI Gray 4 Beak strongly curved, often more than 4 mm long 5 Beak lunately downcurved, not much, if at all exserted from the well-developed lower lip; widespread species of wooded or open slopes and drier meadows in the mountains P. CONTORTA Benth. 5 Beak strongly upcurved, the living flowers reminiscent of an elephant's head with trunk upraised; plant of wet meadows and other wet places P . GROENLANDICA Retz . Penstemon Mitch. Beardtongue 1 Anthers more or less densely long-woolly with tangled hairs (visible with naked eye) 2 Leaves all cauline, the lower reduced, the sterile shoots few and similar to the fertile ones; plants herbaceous P. MONTANUS Greene 2 Larger leaves tending to be clustered near the base of the plant or near the base of the season's growth; usually on short sterile shoots as well as on flowering stems; plants ascending or erect shrubs P. FRUTICOSUS (Pursh)Greene 1 Anthers glabrous, or inconspicuously hispidulous with short, mostly straight hairs 185 3 Flowers white or whitish, plants more or less shrubby at base P. DEUSTUS Dougl. 3 Flowers other than white, mostly blue or purple or if white then not shrubby at base 4 Plants not glandular 5 Plants glabrous throughtout; leaves firm or fleshy often glaucous; flowers large up to 38 mm or inflores- cence more than 1/3 the length of the plant 6 Verticilasters loose; inflorescence secund; flowers large, 18-38 mm P . CYANEUS Pennell 6 Verticilasters dense; inflorescence cylindrical , usually at least 1/2 the length of the plant ; staminode strongly widened at apex and densely golden pubescent P. ARENICOLA A.Nels. 5 Plants pubescent at least in the inflorescence or if glabrous then the inflorescence much less than 1/2 the length of the plant; flowers small 6-16 mm long 7 Flowers small, 6-ll;mm more or less declined P. PROCERUS Dougl. 7 Flower larger, 11-20 mm; scarcely declined P. RYDBERGII A.Nels. 4 Plants more or less glandular in the inflorescence 8 Ovary and capsule ordinarily glandular-puberulent near the summit; calyx elongate 7-13 mm long with herbaceous and entire segments; staminode exserted 9 Plants essentially glabrous below the inflorescence; montane species P . WHIPPLEANUS Gray 9 Plants more or less hairy below the inflorescence, foothills and lowland species P. ERIANTHERUS Pursh 8 Ovary and capsule ordinarily glabrous; calyx seldom over 8 mm long; staminode included 10 Leaves (except for being glandular-hairy in the inflorescence) all glabrous P. ATTENUATUS Dougl. 10 Leaves (all or at least some of the cauline ones) cinereous with numerous very short hairs P. RADICOSUS A.Nels. 186 Veronica L. Speedwell 1 Main stem terminating in an inflorescence, its flowers either densely crowded or more remote and axillary, the upper bract-leaves usually alternate 2 Rhizomatous perennials; seeds numerous 3 Capsules higher than wide; stem (and often also the otherwise glabrous leaves) sparsely to densely villous-hirsute with loosely spreading hairs; stems simple, erect or merely decumbent at the base; filaments 1-1.5 mm long; moderate to high altitude V . WORMSKJOLDII Roem . &Schult . 3 Capsules wider than high; stem finely and closely puberulent; leaves glabrous or nearly so; stems tending to creep at the base, or to produce prostrate lower branches; filaments (1) 2-4 mm long; lowlands to rather high elevations V. SERPYLLIFOLIA L. 2 Annual V. PEREGRINA L. 1 Main stem never terminating in an inflorescence, the leaves opposite throughout and the flowers all in axillary racemes 4 Leaves all short-petiolate; capsules turgid slightly or scarcely notched, slightly if at all wider than high; seeds numerous 0.5 mm long or less V. AMERICANA Schwein. 4 Leaves (at least the middle and upper ones of the flowering shoots) sessile; capsules flattened, conspic- uously notched, evidently wider than high; seeds 5-9 per locule, 1.2-1.8 mm long V. SCUTELLATA L. OROBANCHACEAE Broomrape Family Orobanche L. Broomrape; Cancerroot 1 Flowers subtended by bractlets; calyx not equally 5- cleft; watch for O . ludoviciana which has glabrous anthers O. MULTIFLORA Nutt . 1 Flowers not subtended by bractlets but on naked peduncles; calyx equally 5-cleft O. FASCICULATA Nutt. 187 LENTIBULARIACEAE Bladderwort Family Utricularia L. Bladderwort 1 Flowers large, the lower lip mostly 10-20 mm long; leaves mostly 2-parted at the base, then unequally and quasipinnately several times dichotomous, the segments more or less terete, the ultimate ones filiform, strongly acuminate; bladders abundant, borne on ordinary leaves U. VULGARIS L. 1 Flowers smaller, the lower lip mostly 4-12 mm long; leaves mostly 3-parted at the base, then 1-3 times dichotomous, often unequally, but not quasipinnately so, the segments flat U. MINOR L. PLANTAGINACEAE Plantain Family Plantago L. Plantain; Ribgrass 1 Plants evidently perennial (some species may bloom during the first year) 2 Ovules and seeds 6-30; leaves broad, the well-defined blade broadly elliptic to cordate-ovate and mostly 1.3- 2.3 (3) times as long as wide; plants not woolly at the base; seeds reticulate, 1 mm long; native and introduce mostly weedy plants P.MAJOR L. 2 Ovules 2-4; leaves narrower, the elliptic or narrower blade mostly (2) 2.5-10 times as long as wide, or even longer; plants often woolly at the base; seeds not retic- ulate, well over 1 mm long P . LANCEOLATA L . 1 Plants annual 3 Capsules 4 (6) -seeded; stamens mostly 2; leaves puberulent or glabrous, rarely as much as 3 mm wide; inflorescence wholly glabrous; corolla very small, the lobes less than 1 mm long; bracts ovate, succulent, 2 mm long; plants of saline situations P. ELONGATA Pursh 3 Capsules 2-seeded; stamens 4; leaves more or less woolly- villous to glabrate, often over 3 mm wide; inflorescence sparsely to densely long-hairy; corolla larger, the lobes mostly 1.5-2 mm long; bracts linear or nearly so, firm, mostly longer; plants of nonsaline situations P. PATAGONICA Jacq. 188 RUBIACEAE Madder Family 1 Leaves opposite, with small stipules; ovules basally attached; corolla salverform-funnelform KELLOGGIA GALOIODES Torr . 1 Leaves whorled (or the uppermost sometimes merely opposite); ovules laterally attached (to the partition); corolla diverse GALIUM Galium L . Bedstraw 1 Plants perennial from creeping rhizomes 2 Flowers more or less numerous in a terminal, com- pound and much-branched, rather showy inflorescence; stems prostrate or ascending to more often erect, gla- brous or pubescent, but not retrorsely scabrous on the angles; corollas 4-lobed G. BOREALE L. 2 Flowers solitary or few in small, rather inconspicuous inflorescences; stems weak, tending to recline or scramble on other vegetation, commonly retrorse- scabrous on the angles; corollas 3-lobed or less often 4-lobed G. TRIFIDUM L. 1 Plants annual from a short taproot 3 Leaves 2-4 whorl, not cuspidtate; stem glabrous; fruit with hooked hairs G . BIFOLIUM Wats. 3 Leaves mostly 5-8 whorl, cuspidtate; stem retrorsely scabrous or rarely glabrous; fruits diverse G. APARINE L. 189 CAPRIFOLIACEAE Honeysuckle Family 1 Styles very short or none, the stigmas sessile or nearly so; inflorescence branched and mostly with more or less numerous flowers, umbelliform to corymbiform or pani- culiform; corolla rotate to shortly open-campanulate SAMBUCUS RACEMOSA L. 1 Style well developed, more or less elongate; inflorescence various, of paired flowers at the end of a peduncle, or of short racemes or spikes, or of sessile verticels on an elongate or foreshortened axis, but not umbelliform , corymbiform nor paniculiform; corolla short-campanulate to elongate and tubular not at all rotate; leaves simple 2 Stamens as many as the corolla lobes , mostly 5; fruits fleshy; plants not at once trailing and with flowers paired on terminal peduncles 3 Corolla regular or merely ventricose (the tube unequally expanded, somewhat bulged on one side); ovary with 2 fertile uniovulate locules and 2 sterile locules with several abortive ovules each; fruit white, drupaceous, with 2 seedlike stones SYMPHORICARPOS 3 Corolla evidently irregular, either 2-lipped, or spurred at the base or both; ovary mostly 2- to 3- locular , with several ovules in each locule; fruit a several-seeded berry, red to blue or black LONICERA 2 Stamens 4, corolla lobes 5; fruits dry; trailing plants with the flowers mostly paired on terminal peduncles LINNAEA BOREALIS L . Lonicera L. Honeysuckle 1 Bracts at the summit of the peduncle enlarged, broad and foliaceous, often anthocyanic, forming an involucre, the outer pair 8-15 mm long or more; ovaries and fruits wholly distinct L . INVOLUCRATA (Rich.) Banks 1 Bracts at the summit of the peduncle narrow and mostly small, relatively inconspicuous, less than 5 mm long except in forms of L . caerulea 190 2 Bractlets (inner bracts) wholly connate into a narrow- mouthed cup which tightly encloses the ovaries and grow with them into a fruit, the ovaries thus appearing wholly united, but actually distinct within the cup; corolla yellow, obscurely or scarcely bilabiate, the lobes about as long as the tube L. CAERULEA L. 2 Bractlets small and inconspicuous, or obsolete, not enclosing the ovaries; ovaries and fruit united at least at the base, but obviously paired L. UTAHENSIS Wats. Symphoricarpos Duhmel . Snowberry 1 Corolla relatively short and broad, short-campanulate , not much, if at all, longer than wide (pressed), often bulged on one side (ventricose) , the lobes varying from half as long to longer than the tube 2 Style elongate, (3) 4-7 (8) mm long, more or less exserted, long-hairy near the middle or occasionally glabrous; anthers about 1.5-2 mm long, evidently shorter than the filaments; corolla lobes mostly equal- ing or a little longer than the tube S. OCCIDENTALIS Hook. 2 Style short, 2-3 mm long, glabrous; anthers about 1-1.5 mm long, not much, if at all, shorter than the filaments; corolla-lobes often evidently shorter than the tube S. ALBUS (L . ) Blake 1 Corolla relatively long and narrow, elongate-campanulate evidently longer than wide, not evidently ventricose, the lobes mostly 1/4-1/2 as long as the tube; erect shrubs with short styles S . OREOPHILUS Gray 191 VALERIANACEAE Valeriana L. 1 Plants with a stout taproot and short, branched caudex; basal leaves tapering more or less gradually to the petiolar base; inflorescence more or less paniculiform even at anthesis V. EDULIS Nutt . 1 Plants with a stout rhizome or caudex and numerous fibrous roots; lower leaves with mostly sharply differen- tiated blade and petiole; inflorescence corymbiform at anthesis, though often more expanded in fruit 2 Relatively small plants, 1-4 (6) dm tall, not very leafy, the lateral lobes of the cauline leaves mostly well under 1 cm wide; achenes lanceolate, glabrous V. DIOICA L. 2 Relatively robust plants, 3-9 dm tall, tending to be amply leafy the lateral lobes of some of the cauline leaves often over 1 cm wide; achenes a little broader, mostly lance-ovate, short-hairy or occasionally glabrous V. OCCIDENTALIS Heller CAMPANULACEAE Harebell Family 1 Filaments and anthers distinct; corolla regular CAMPANULA ROTUNDIFOLIA L . 1 Filaments and anthers united into a tube, two of the anthers shorter than the others , the orifice of the tube thus oblique or appearing lateral; corolla distinctly irregular (or want- ing in some flowers) PORTERELLA CARNULOSA (H.& A.) Torr. 192 COMPOSITAE ARTIFICIAL KEYS TO THE GENERA 1 Flowers all ligulate and perfect; juice milky; Group VI (201) 1 Flowers not all ligulate; ray (ligulate) flowers when present marginal, either pistillate or neutral; juice ordinarily watery 2 Heads radiate 3 Rays yellow or orange (sometimes marked with pur- ple or reddish brown at the base) 4 Pappus chaffy, or of firm awns, or none; recep- tacle chaffy, bristly, or naked GROUP I (193) 4 Pappus partly or wholly of capillary (sometimes plumose) bristles; receptacle naked GROUP II (195) 3 Rays white to pink-purple, red, or blue, not yellow or orange GROUP III (196) 2 Heads discoid or disciform, without rays (some plants with very small and inconspicuous rays are keyed here as well as in the radiate group) 5 Pappus partly or wholly of numerous capillary (some- times plumose) bristles GROUP IV (197) 5 Pappus of scales, or awns, or very short chaffy bristles, or a mere crown, or none, never plumose GROUP V (200) Group I. Rays yellow or orange; pappus chaffy, or of firm awns , or none 1 Receptacle chaffy or bristly throughout 2 Involucral bracts in two distinct, dissimilar series; achenes strongly flattened at right angles to the radius of the head BIDENS CERNUA L. 2 Involucral bracts in one or more series, all of more or less similar nature; achenes either not much com- pressed or compressed parallel to the radius of the head 3 Receptacle merely bristly; leaves alternate, or rarely all basal GAILLARDIA ARISTATA Pursh 3 Receptacle chaffy, provided with definite bracts rather than mere bristles; leaves various 193 4 Plants subscapose, cauline leaves much reduced B ALS AMORHI ZA SAGITTATA (Pursh) Nutt. 4 Plants evidently leafy stemmed, although the basal leaves maybe larger than the cauline ones 5 Cauline leaves all alternate 6 Receptacle flat or merely convex; rays pistillate and fertile; leaves entire or merely toothed WYETHIA 6 Receptacle conic or columnar; rays neutral; leaves various 7 Rays subtended by receptacular bracts; achenes flattened, with 2 sharp and often 2 very blunt angles; leaves pinnatifid RATIBIDA COLUMNIFERA (Nutt . ) Woot. & Standi. 7 Rays not subtended by receptacular bracts; achenes equably quadrangular, or somewhat compressed, not strongly flattened; leaves entire to pinnatifid RUDBECKIA OCCIDENTALIS Nutt 5 Cauline leaves, or at least the lower ones, opposite 8 Pappus none; rays mostly 7-17 mm long VIGUIERA MULTIFLORA (Nutt.) Blake 8 Pappus present, though sometimes readily deciduous; rays mostly 1.5-5 cm long 9 Pappus persistent; disk achenes strongly com- pressed, thin-edged HELIANTHELLA 9 Pappus readily deciduous (at least as to the two principal awn scales); achenes only slightly or moderately compressed HELIANTHUS Receptacle naked, or with a single row of chaff between the rays and disk flowers (sometimes only a few or even only a solitary disk flower present) 10 Rays well developed and conspicuous, mostly 5-30 mm long; receptacle naked 11 Involucral bracts few, mostly 5-13 (15), mostly sub- equal and subuniseriate, tending to subtend the rays individually; rays 5-13 ERIOPHYLLUM LANATUM (Pursh) Forbes 194 11 Involucral bracts many, mostly 20 or more in 2-3 subequal series, usually not individually subtending the 35-55 ray flowers HULSEA ALGIDA Gray 10 Rays short and inconspicuous, mostly 1-5 mm long 12 Involucral bracts well imbricate in several series GUTIERREZIA SAROTHRAE (Pursh) Britt. & Rusby 12 Involucral bracts essentially uniseriate MADIA GLOMERATA Hook. Group II. Rays yellow or orange; pappus partly or wholly of capillary bristles 1 Shrubs HAPLOPAPPUS 1 Herbs 2 Leaves (except sometimes the reduced uppermost ones) opposite ARNICA 2 Leaves alternate, or all basal 3 Involucral bracts uniseriate, equal, narrow, commo with a few very much shorter outer ones at the base; style branches truncate, exappendiculate , minutely penicillate SENECIO 3 Involucral bracts in 2 or more series, equal or im- bricate, narrow or broad; style branches with short or elongate, externally hairy appendages 4 Plants with numerous fibrous roots arising from a rhizome or short caudex, without a taproot; heads few to generally more or less numerous, small, the involucre mostly 2-7 mm high; pappus bristles mostly equal and white SOLIDAGO 4 Plants taprooted except for a few species that have solitary heads; heads often larger; pappus various 195 Style appendages very short, 0.5 mm long or less; in vol ucral bracts subequal or more or less imbricate, often green in part, but neither definitely leafy nor with chartaceous base and herbaceous green tip ERIGERON LINEARIS (Hook.) Piper Style appendages longer, mostly 0.7 mm long or more; involucre various 6 Pappus double, the outer much shorter than the inner CHRYSOPSIS VILLOSA var . DEPRESSA (Purs.)Nutt. 6 Pappus simple, the bristles generally unequal, but not divided into two lengths HAPLOPAPPUS Group III. Rays white to pink, purple, red, or blue 1 Receptacle chaffy or bristly throughout; pappus of scales or awns, or very short chaffy bristles, or a mere crown, or none 2 Rays very large, mostly 1.5-5 cm long; perennial WYETHIA 2 Rays smaller, seldom over about 1 cm long; annual or perennial ACHILLEA MILLEFOLIUM L . 1 Receptacle naked, or with a row of chaff between the ray and disk flowers; pappus various 3 Pappus of the disk flowers composed partly or wholly of capillary bristles; receptacle naked 4 Rays very numerous, filiform, and short, scarcely longer than the disk flowers; annual weeds, bloomin chiefly in late summer and fall, with the involucre and style nearly of Erigeron CONYZA CANADENSIS (L . ) Cronq. 4 Rays well developed and conspicuous, obviously surpassing the disk, except for a few species which are either longer-lived or have the involucre and style of Aster 196 5 Involucral bracts subequal or more or less imbricate, often green in part, but neither definitely leafy nor with chartaceous base and herbaceous green tip; style appendages lanceolate or broader, acute to obtuse, 0.5 mm long or less; plants blooming chiefly in spring and early summer (or in midsummer at high elevations) ERIGERON 5 Involucral bracts either subequal and the outer leafy, or more commonly evidently imbricate, with chartaceous base and evident green tip, sometimes chartaceous throughout; style appendages lanceolate or narrower, acute or acuminate, ordinarily more than 0.5 mm long; plants blooming chiefly in late summer and fall (or in midsummer at high elevations) 6 Plants distinctly taprooted; leaves spinulose-tipped and often spinulose-toothed or pinnatifid; style appendages generally longer than the stigmatic part MACHAERANTHERA 6 Plants otherwise, most species fibrous rooted, often rhizomatous; leaves entire or toothed, but not spinu- lose; style appendages generally shorter than the stigmatic part ASTER 3 Pappus of scales, or awns, or distinctly flattened, chaffy bristles or a mere crown, or none; receptacle naked, or with a row of bracts between the ray and disk flowers 7 Receptacle evidently conic or hemispheric MATRICARIA MATRICARIOIDES (Less . ) Porter 7 Receptacle flat or nearly so, sometimes very small 8 Pappus of the disk flowers of about 10 or more flattened, bristlelike scales TOWNSENDIA 8 Pappus lacking CHRYSANTHEMUM LEUCANTHEMUM L . Group IV. Heads discoid or disciform; pappus capillary 1 Leaves either more or less spiny and thistlelike, or heads with densely bristly receptacle, or both 2 Plants thistlelike with more or less spiny-margined leaves and usually also with spiny involucre 197 3 Pappus bristles merely barbellate CARDUUS NUTANS L . 3 Pappus bristles plumose (or those of the outermost row of flowers sometimes merely barbellate); recept- acle densely bristly CIRSIUM 2 Plants scarcely or not at all thistlelike, the leaves not spiny-margined; involucre not spiny CENTAUREA MACULOSA Lam . Leaves not at all thistlelike; receptacle naked 4 Shrubs 5 Involucral bracts 4-6, equal TETRAD YMIA CANESDENS DC . 5 Involucral bracts more numerous, imbricate, or at least in several series CHRYSOTHAMNUS 4 Herbs 6 Flowers all perfect and fertile (heads discoid) 7 Leaves opposite; flowers yellow or orange ARNICA 7 Leaves alternate, or if rarely opposite or whorled, then the flowers not yellow or orange 8 Principal involucral bracts essentially equal and uniseriate, although some very much reduced outer bracts may be present SENECIO 8 Principal involucral bracts more or less imbri- cate in 2-several series 9 Style branches flattened, with well developed, introrsely marginal stigmatic lines and a short or elongate, externally hairy appendgae; flowers usually yellow, occasionally reddish; pappus merely barbellate 10 Style appendages very short, 0.5 mm long or less ERIGERON 10 Style appendages longer, mostly 0.7 mm long or more 11 Plants either caudiciferous , fibrous- rooted, and tall (6-12 dm), or if smaller and taprooted then short-lived (barely perennial) and with the herbage evi- dently canescent-puberulent ASTER BRACHYACTIS Blake 11 Plants not with the foregoing combination of characters HAPLOPAPPUS MACRONEMA Gray 198 9 Style branches with short stigmatic lines and an elongate, papillate appendage; flowers cream, white, to pink-purple, not yellow BRICKELLIA GRAND IF OR A (Hook . ) Nutt . 6 Flowers, the outer, or in some heads, all, pistillate (head disciform); (some dioecious plants, in which some heads are wholly pistillate, and other wholly hermaphrodite, are keyed here) 12 Herbage more or less white-woolly; leaves simple and entire or nearly so; involucral bracts mostly with dry, scarious, thin, white to yellowish, brownish, or blackish-green tips 13 Plants taprooted, or perennial; heads all with outer pistillate and central perfect (or functionally stam- inate) flowers GNAPHALIUM 13 Plants fibrous-rooted, perennial, often with rhizomes or stolons, but without a taproot; dioe- cious or nearly so, the heads on at least some of the plants wholly staminate, or wholly pistillate 14 Basal leaves generally forming a conspicuous, persistent tuft; stem seldom very leafy, with or without stolons and rhizomes; strictly dioecious (staminate plants rare in some species) ANTENNARIA 14 Basal leaves soon deciduous, not markedly larger than the numerous and well developed cauline ones; plants with rhizomes, but no stolons; pistillate plants commonly with a few central, functionally staminate flowers in each head ANAPHALIS MARGARITACEA (L.) B.&H. 12 Herbage not at all white-woolly, though often other- wise pubescent; involucral bracts not markedly scarious at the tip 15 Perennial ERIGERON 15 Annual CONYZA CANADENSIS (L . ) Cronq. 199 Group V. Heads discoid or disciform; pappus chaffy, or of awns , or none 1 Receptacle chaffy or bristly throughout, or a few of the central flowers bractless 2 Receptacle elongate, the large black heads thus shaped like the end of a finger or thumb RUDBECKIA OCCIDENTALIS Nutt. 2 Receptacle flat or merely convex; heads not black (invol ucre blackish in spp . of Centaurea) 3 Heads very small, the involucre only 1.5-4 mm high, the disk up to about 5 mm wide IVA 3 Heads obviously larger; involucre 6-40 mm high, the disk seldom less than 1 cm wide 4 Receptacle chaffy; involucral bracts biseriate and obviously dimorphic; achenes basifixed BIDENS CERNUA L . 4 Receptacle bristly; involucral bracts not divided into two distinct series; achenes obliquely attached to the receptacle CENTAUREA MACULOSA Lam. 1 Receptacle naked, or with a single row of chaffy bracts between the ray and disk flowers (heads sometimes short and very few-flowered) 5 Plants with an evident though sometimes short pappus of distinct awns or scales 6 Pappus of a few firm, deciduous awns; involucre strongly resinous GRINDELIA SQUARROSA (Pursh) Dunal 6 Pappus of scales; involucre sometimes glandular, but scarcely resinous CHAENACTIS 5 Plants without a pappus, or the pappus a mere minute crown 7 Involucral bracts uniseriate and equal, each sub- tending and wholly enclosing an achene; linear- leaved annuals with minute rays MADIA GLOMERATA Hook . 7 Involucral bracts in several series, not enclosing the achenes; flowers various 8 Inflorescence spiciform, racemiform, or panicu- liform ARTEMISIA 8 Inflorescence corymbiform to capitate, or the heads solitary 200 9 Receptacle high, hemispheric or conic at least at maturity MATRICARIA MATRICARIOIDES (Less . ) Porter 9 Receptacle flat or somewhat convex TANACETUM VULGARE L. Group VI. Flowers all ligulate 1 Pappus of simple (sometimes barbellate) capillary bristles only (some of the outer bristles sometimes evidently stronger than the others) 2 Achenes more or less strongly flattened; some of the pappus bristles no more than 4-celled in cross-section at the base; corolla tube mostly more than half as long as the ligule; our species erect, leafy-stemmed, and commonly with several or many heads 3 Achenes beakless, without any enlarged pappiferous disk at the summit; some of the outer pappus bristles evidently stouter than the others; heads mostly many- flowered (about 85- to 250-flowered in our species) SONCHUS ASPER (L . ) Hill 3 Achenes beaked or less often beakless, in either case somewhat enlarged at the summit where the pappus is attached; none of the pappus bristles much stouter than the others; heads relatively few- flowered (about 11- to 56-flowered in our species) LACTUCA 2 Achenes terete or prismatic, scarcely flattened; pappus, corolla, and habit various 4 Achenes smooth or nearly so, not evidently spinu- lose or muricate 5 Perennial from a elongate or (in all our species) very short rhizome, with numerous fibrous roots; taproot wanting; achenes truncate or sometimes narrowed upwards , not beaked; pappus mostly sordid or brownish HIERACIUM 5 Annual, biennial, or more often perennial, from a taproot or several strong roots, without rhizomes (some of the Old World species of Crepis are truly rhizomatous rather than taprooted); achenes beaked or beakless; pappus mostly white or nearly so 201 6 Plants with at least a few cauline leaves; heads several or numerous to rarely solitary; involucre more or less calyculate CREPIS 6 Plants scapose or nearly so, with strictly solitary heads; involucral bracts imbricate or subequal 7 Achenes evidently beaked at maturity (except some- times in one variety of Agoseris glauca that has con- spicuously pubescent herbage and involucre) AGOSERIS 7 Achenes beakless, herbage and involucre glabrous or nearly so MICROSERIS 4 Achenes spinulose or muricate near the summit of the body, tipped by a slender beak; plants scapose, mono- cephalous; involucre more or less calyculate; flowers yellow in our species TARAXACUM 1 Pappus of plumose bristles, or bristles and scales, or scales, or minute awns, or none, the scales sometimes very slender and bristle-like in species of Microseris 8 Flowers pink or occasionally white; principal bracts few, in our species mostly 3-8; pappus plumose at least above STEPHANOMERIA 8 Flowers yellow or orange to sometimes purple, not pink; principal bracts often more numerous 9 Pappus of scales, these sometimes narrow, and often with a terminal (in one species plumose) awn, or in one species of intermingled capillary bristles and narrow, gradually attenuate scales; achenes sometimes narrowed above, but not beaked MICROSERIS 9 Pappus (except sometimes in the marginal flowers) of plumose bristles, sometimes with some shorter outer nonplumose bristles or scales; achenes beaked or beakless TRAGOPOGON Agoseris Raf. False Dandelion, Mountain Dandelion 1 Achenes generally with a short, stout, more or less striate beak up to about half as long as the body (beak sometimes longer in var. laciniata, sometimes wanting in var. dasycephala); flowers yellow, often drying pinkish A. GLAUCA (Pursh) Raf. 1 Achenes with a long, slender, scarcely or not at all striate beak, more than half as long as the body of achene; flowers burnt orange A. AURANTIACA (Hook.) Greene 202 Antennaria Gaertn. Everlasting; Pussy-toes Heads solitary, terminal; low plants, the flowering stems mostly less than 1 dm tall A. DIMORPHA (Nutt . ) T. & G. Heads several or many; plants often well over 1 dm tall 2 Upper surfaces of the basal leaves distinctly less pubescent than the lower, sooner or later glabrate A. RACEMOSA Hook. 2 Upper surfaces of the basal leaves nearly or quite as densely hairy as the lower, glabrate, if at all, only in extreme age (rarely soon glabrate in forms of A. alpina) 3 Plants mat-forming, with numerous leafy stolons 4 Terminal scarious protion of the involucral bracts, at least the middle and outer ones, discolored and brownish to dirty blackish green; montane and alpine 5 Terminal scarious portion of the involucral bracts dirty blackish green throughout; involucral bracts usually sharp-pointed; alpine and subalpine A . ALPINA (L . ) Gaertn . 5 Terminal scarious portion of the inner involucral bracts becoming white at the tip, or the whole scarious portion merely discolored and rather pale brown; involucral bracts usually blunt; montane, but seldom alpine A . UMBRINELLA Rydb . 4 Terminal scarious portion of the involucral bracts white or pink, sometimes with a basal dark spot; lowland to montane plants, but scarcely alpine 6 Involucral bracts with a conspicuous black spot at the base of the scarious portion; basal leaves narrowly oblanceolate A. CORYMBOSA E. Nels. 6 Involucral bracts scarcely or not at all darkened at the base of the scarious portion; leaves usually broader 7 Heads large, the involucre 7-11 mm high, the dry pistillate corollas mostly 5-8 mm long; uncommon A. PARVIFOLIA Nutt. 203 7 Heads smaller, the involucre 4-7 mm high, the dry pistil- late corollas mostly 2.6-4.5 mm long; common and widespread A. MICROPHYLLA Rydb. Plants without stolons, mostly not mat-forming, though often with several or many stems arising from a branched subterranean rhizome or caudex 8 Involucre scarious to the base, glabrous or nearly so, the outermost bracts occasionally a little woolly at the base A . LUZULOIDES T . & G . 8 Involucre with a densely pubescent, not at all scarious lower portion, the pubescence extending even to the inner bracts 9 Plants mostly 1-2 dm tall; involucre blackish in aspect, although the inner bracts may be white at the tip A. LANATA (Hook.) Greene 9 Plants mostly 2-5 dm tall A . ANAPHALOIDES Rydb . Arnica L. Arnica Cauline leaves mostly 5-12 pairs 2 Involucral bracts obtuse or merely acutish, bearing a tuft of long hairs at or just within the tip A. CHAMISSONIS Less. 2 Involucral bracts more or less sharply acute, the tip not markedly more hairy than the body A. LONGIFOLIA D.C.Eat. Cauline leaves mostly 2-4 pairs, not including those (if any) of the basal cluster 3 Heads characteristically discoid (marginal corollas sometimes ampliate, rarely truly radiate) A. PARRYI Gray 3 Heads characteristically radiate (rare rayless forms occur, chiefly in company with the normal radiate plants) 4 Pappus subplumose, more or less tawny; no evident tufts of basal leaves on the flowering stem 5 Heads narrow, more or less turbinate; cauline leaves ovate or deltoid to broadly elliptic or lance- elliptic A . DIVERSIFOLIUS Gr eene 5 Heads broader, subhemispheric; cauline leaves more variable A . MOLLIS Hook. 204 4 Pappus merely barbellate, usually white or nearly so; basal leaves often conspicuous, sometimes small or wanting 6 Leaf blades relatively broad, the larger ones mostly 1-2.5 (or rarely 3) times as long as wide; basal leaves sometimes persistent, but not densely tufted 7 Achenes generally glabrous below, or glabrous throughout; basal leaves (those on separate short shoots) seldom cordate when present, the cauline leaves even less frequently so; leaves generally more or less toothed; involucre with few or no long hairs A . LATIFOLIA Bong . 7 Achenes mostly short-hairy (or glandular) nearly or quite to the base; leaves and involucre various A . CORDIFOLIA Hook . 6 Leaf blades narrower, mostly 3-10 times as long as wide; basal leaves often densely tufted, but not always so 8 Heads relatively large, hemispheric or nearly so, with mostly 10-23 rays; lower cauline leaves gener- ally petiolate; foothills and moderate elevations in the mts . 9 Old leaf bases with dense tufts of long brown wool in the axils; disk corollas with some spreading glandless hairs, as well as commonly stipitate- glandular A . FULGENS Pursh 9 Old leaf bases without axillary tufts, or the hairs few and white; disk corollas stipitate- glandular , generally not otherwise hairy A. SORORIA Greene 8 Heads smaller, turbinate-campanulate, with mostly 7-10 rays; lower cauline leaves tending to be sessile; alpine and subalpine A. RYDBERGII Greene Artemisia L. Sagebrush; Wormwood 1 Marginal flowers pistillate; herbs or shrubs 2 Disk flowers fertile, with normal ovary 3 Receptacle not hairy 4 Perennial from a rhizome or caudex, or sometimes from a taproot; plants more or less hairy, at least on the lower surfaces of the leaves when young 205 5 Leaves ordinarily with one or two pairs of stipule like lobes at the base; divisions of the principal leaves again toothed, cleft or lobed; introduced, weedy, rare in our range A. VULGARIS L. 5 Leaves ordinarily without stipule-like lobes at the base, variously entire to bipinnatifid; native 6 Leaves small and finely divided, the best dev- eloped ones about 2-5 cm long, bipinnatifid; often with the ultimate segments again toothed; widespread A. MICHAUXIANA Bess. 6 Leaves less divided and often larger, varying from entire to pinnatifid or occasionally sub- bipinnatifid A. LUDOVICIANA Nutt. 4 Annual or biennial from a taproot; leaves green, essentially glabrous A . BIENNIS Willd. 3 Receptacle beset with numerous long hairs between flowers; leaves dissected 7 Plants mat-forming and subshrubby, with numer- ous heads; leaf blades up to 12 mm long A. FRIGIDA Willd. 7 Plants strictly herbaceous and not at all mat-form- ing; cauline leaves few; heads few, mostly 5-25; at least some of the basal leaves with blades 1. 5 cm long or more A . SCOPULORUM Gray 2 Disk flowers sterile, with abortive ovary 8 Leaves mostly entire, or the lower sometimes with 3-5 long narrow segments A. DRACUNCULUS L. 8 Leaves pinnatifid, bipinnatifid, or dissected, except the uppermost A . CAMPESTRIS L. Flowers all perfect; shrubs (Sagebrush) 9 Leaves all or nearly all entire A. CANA Pursh 9 Leaves , or many of them 3-toothed at the apex or 3- to 5 -cleft 10 Leaves, or many of them, deeply cleft into linear or linear-oblanceolate divisions which may themselves be 3-cleft; flowers mostly 5-8 in each head; inflores- cence rather loosely paniculiform A. TRIPARTITA Rydb . 206 10 Leaves mostly merely toothed at the apex (occasionally more deeply cleft forms differ in other respects from A. tripartita) 11 Plants dwarf, mostly 1-4 dm tall, with spikelike to narrowly paniculiform inflorescence seldom as much as 1.5 cm wide A . ARBUSCULA Nutt . 11 Plants taller, mostly 4-20 dm tall, with more paniculi- form inflorescence that is mostly 1.5-7 cm wide A. TRIDENTATA Nutt. Aster L. Aster; Michaelmas Daisy 1 Annuals with slender, short, inconspicuous rays only slightly exceeding the disk, or the pistillate flowers with tubular-filiform, rayless corolla; pistillate flowers more numerous than the disk flowers (Brachyactis) A. BRACHYACTIS Blake 1 Annuals, biennials, or most commonly perennials , most species with well developed rays (short and inconspicu- ous in a few perennials, or the pistilllate flowers com- pletely wanting in a few perennials); pistillate (ray) flowers mostly fewer than the disk flowers 2 Pappus distinctly double, with an outer series of very short bristles in addition to the principal bristles; heads solitary; leaves numerous, narrow (up to 4 mm wide) , uniform (Ionactis) A. SCOPULORUM Gray 2 Pappus simple or occasionally more or less double; habit various; but not as in Ionactis 3 Plants with a taproot or with an erect, taprootlike caudex, without rhizomes or numerous fibrous roots; style appendages equalling or longer than the stigma- tic portion; rays blue or purple A. ALPIGENUS (T.&G.) Gray 3 Plants fibrous-rooted, often with creeping rhizomes, without a taproot or taprootlike caudex (or sometimes with a taproot in a white-rayed species of Eucephalus) style appendages in most species shorter than the stigmatic portion 207 4 Rays few, typically about 5, 8, or 13, sometimes 21 (or the pistillate flowers completely wanting); involucral bracts tending to be keeled, seldom strongly herbaceous; lower stem leaves clearly reduced, plants without well developed creeping rhizomes (Eucephalus) 5 Outer involucral bracts rounded to slightly acutish A. GLAUCODES Blake 5 Outer involucral bracts sharply acute or acuminate 6 Leaves large, mostly 15-35 mm wide, 2.5-6 times as long as wide; rays white (often becoming pinkish in age or in drying); robust plants, mostly 6-15 dm tall A . ENGELMANNII (Eat . ) Gray 6 Leaves smaller, 3-15 mm wide; smaller plants, up to 6 or rarely 8 dm tall A . PERELEGANS Nels . & Macbr . 4 Plants differing in one or more respects from the section Eucephalus as described above 7 Achenes 3-nerved, flattened; monocephalous , arctic- alpine plants with the habit of Erigeron (Amellastrum) A. ALPINUS L. 7 Achenes mostly several-nerved; plants of various, but mostly not arctic-alpine habitats, mostly not at all erigeroid in habit (Euaster) 8 Involucre and peduncles glandular 9 Leaves mostly sharply serrate or dentate, sessile, gradually larger toward the middle of the stem, wit the lower leaves soon deciduous; involucral bracts strongly imbricate A . CONSPICUUS Lindl . 9 Leaves entire, the upper leaves sessile, clasping, strongly reduced from the persistant, petiolate lower leaves; involucre seldom much imbricate A . INTEGRIFOLIUS Nutt . 8 Involucre and peduncles, as well as the rest of the plant, without glands, or apparently so 10 Disk corollas with the tube equaling or generally surpassing the slender limb; involucre often more or less suffused with anthocyanin A. SIBIRICUS L. 10 Disk corollas with the tube distinctly shorter than the limb; involucral bracts sometimes purple-tipped, but normally not distinctly purple- margined or suffused with anthocyanin except in some forms of A . foliaceus 208 11 Pubescence of the stem and branchlets occurring in lines decurrent from the leaf bases, commonly neither uniform under the heads nor confined to the inflorescence; inflor- escence generally large and leafy A. HESPERIUS Gray 11 Pubescence of the stem uniform, or, if in lines, then either uniform under the heads or very scanty and con- fined to the inflorescence; inflorescence various 12 Involucral bracts, at least the outer, with loose or squarrose, minutely spinulose-mucronate tip; rays white A. FALCATUS Lindl . 12 Involucral bracts not spinulose-mucronate at the tip (rarely obscurely so in A. chilensis) , variously appressed to spreading; rays white or more often colored 13 Involucres strongly graduated, at least the outer bracts obtuse, markedly shorter than the inner, and not foliaceous A . CHILENSIS Nees . 13 Involucres not strongly graduated, or, if so, then the bracts markedly acute; involucral bracts acute, or, if obtuse, then enlarged and foliaceous 14 Inflorescence a long narrow leafy panicle with usually numerous heads; stem pubescence mostly uniform and short; leaves mostly over 7 times as long as wide; rays usually pink or white A . EATONII (Gray) Howell 14 Inflorescence few-headed, or, if with many heads , then shorter, more open, and cymose-paniculate often with much reduced leaves; leaves and pubescence various; rays usually blue or violet 15 Leaves and involucral bracts relatively small and narrow, the middle cauline leaves mostly less than 1 cm wide and more than 7 times as long as wide, the involucral bracts small and linear or linear-oblong, never enlarged and leafy A . OCCIDENTALIS (Nutt . )T . & G . 15 Leaves and involucral bracts relatively large, the middle cauline leaves mostly over 1 cm wide (narrower in reduced alpine plants) and less than 7 times as long as wide, some of the involucral bracts often more or less enlarged and leafy (sometimes all narrow and linear) A. FOLIACEUS Lindl. 209 Chaenactis DC . 1 Alpine perennial with 1 or usually several rosettes, the naked axillary peduncles up to 1 dm long, otherwise stemless C. ALPINA (Gray) Jones 1 Leafy- stemmed biennials or perennials, with or without rosettes, seldom alpine C. DOUGLASII (Hook.)H.&A. Chrysothamnus Nutt. Rabbit Brush 1 Twigs glabrous or minutely spreading-puberulent , not at all tomentose C. VISCIDIFLORUS (Hook.)Nutt. 1 Twigs covered with a feltlike tomentum, this sometimes so close as to escape casual observation 2 Outer involucral bracts regularly shortened, not herb- aceous-tipped C. NAUSEOSUS (Pall.) Britt. 2 Outer involucral bracts commonly prolonged into a slender herbaceous tip or appendage C. PARRYI (Gray) Greene Cirsium Mill. Thistle From Gardner (1972) 1 Involucre of largest mature heads (0.9-) 1.2-1.7 (-2) cm tall, 0.6-1 cm broad at base; heads numerous, in loose clusters, corymbiform; heads of two kinds, if pappus longer than corolla, anthers 1-2 mm long, if pappus shorter than corolla, anthers 4-5 mm long C. ARVENSE (L.) Scop. 1 Involucre of largest mature heads more than 1.8 cm tall, and 1 cm or more broad at base; heads solitary or in compact terminal clusters or axillary, not corymbiform; regardless of pappus/corolla relationship, all anthers similar in length 2 Heads frequently in terminal cluster, occasionally axillary on upper half of stem; all heads exceeded by one to several cauline leaves; leaves not markedly reduced upwards; phyllaries without a glutinous dorsal ridge (except a few glands on an occasional specimen of C . tweedyi) 3 Pappus longer than the corolla by 1 mm or more; achenes 4 mm long and 2 mm or less broad C. FOLIOSUM (Hook.) DC. 210 3 Pappus shorter than the corolla; achenes longer than 4mm and 2 mm or more broad 4 Leaf bases of most cauline leaves decurrent, wings 6-30 mm long; leaves glabrous above and below, rarely a thin tomentum below; involucre 1-1.5 cm broad at base C . TWEEDYI Rydb . 4 Leaf bases of all leaves clasping, not decurrent; leaves tomentose below; involucre 1.5-3 cm broad at base C. SCARIOSUM Nutt . 2 Heads borne singly or in loose clusters, always one terminal on stem and branches, occasionally axillary on upper half of stem; heads never appreciably exceeded by cauline leaves; leaves markedly reduced upwards; phyllaries with or without a glutinous dorsal ridge 5 Upper leaf surfaces with minute, appressed spines, otherwise glabrous; outer phyllaries to 1 mm broad at base and reflexed near middle C. VULGARE (Savi) Airy-Shaw 5 Upper leaf surfaces without minute, appressed spines, either glabrous or tomentose; outer phyllaries 1-3 mm broad at base, not reflexed, although spines may be reflexed at base 6 Leaves clasping stem, rarely decurrent, if so, wings less than 12 mm long 7 Yellow apical collar on achenes 0.4-0.7 mm broad; rosette leaves, at least a few, and occasionally all cauline leaves entire, with marginal spines; upper leaf surface usually green C . FLODMANII (Rydb . ) Arthur 7 Yellow apical collar on achenes to 0.2 mm broad or lacking; rosette leaves and cauline leaves dissected, rarely subentire, upper leaf surface usually gray C. UNDULATUM (Nutt.) Spreng. 6 Leaves decurrent, wings of middle cauline leaves at least 15 mm long C. SUBNIVEUM Rydb. Crepis L. Hawk's-beard 1 Introduced annual or biennial weeds of lawns and waste places C. TECTORUM L. 1 Native perennial species, not weedy 2 Stem and leaves glabrous, or more or less hispid, but not at all tomentose 211 3 Flowers mostly 9~12 in each head; plants commonly 1-3 dm tall C. ELEGANS Hook. 3 Flowers mostly 20-50 in each head; plants mostly 2-7 dm tall C. RUNCINATA (James) T.&G. 2 Stem and leaves more or less tomentose or puberulent, at least when young, sometimes also setose or glandular- hispidulous 4 Involucres, or lower part of stem, or both, conspicu- ously setose, but not at all glandular (forms of C. atrabarba , recognizable by the deeply pinnatifid leaves with narrow, entire segments, might be sought here) C. MODOCENSIS Greene 4 Involucres and stem sparingly or not at all setose, or, if evidently setose, then the setae gland-tipped 5 Heads very narrow, mostly 5- to 10-flowered, with 5-7 (8) inner involucral bracts, which are glabrous or occasionally tomentulose; well developed plants mostly with 20-100 or more heads C. ACUMINATA Nutt. 5 Heads broader, mostly 10- to 40-flowered, with 8-15 inner involucral bracts, these never glabrous; heads 3-30, or rarely 40 6 Leaf segments linear or narrowly lanceolate, mostly entire; achenes generally greenish C. ATRABARBA Heller 6 Leaf segments broader, mostly lanceolate or deltoid, some of them usually toothed; achenes mostly yellowish or brownish C. OCCIDENTALIS Nutt. Erigeron L. Daisy; Fleabane 1 Pistillate corollas very numerous, filiform, with very narrow short erect rays, these sometimes not exceeding the disk, or the inner pistillate corollas tubular and rayless; involucre glandular or hirsute or both, but not woolly-villous 2 Rayless pistillate flowers present between the rays and disk flowers; inflorescence corymbiform, the peduncles arcuate or obliquely ascencing, or the head solitary E. ACRIS L. 212 2 Rayless pistillate flowers wanting; inflorescence racemiform, the peduncles erect or nearly so, or the head solitary E . LONCHOPHYLLUS Hook. Pistillate corollas few to numerous (rarely absent) , the tube generally cylindrical, the rays well developed and spreading, or occasionally reduced or absent, but not short, narrow and erect except in a few high-northern species with woolly-villous involucre 3 Pappus of the ray and disk flowers unlike , that of the disk flowers composed of bristles and short outer setae, that of the ray flowers lacking the bristles E. STRIGOSUS Muhl. 3 Pappus of the ray and disk flowers alike, of bristles sometimes also with outer setae or scales 4 Cauline leaves ample, usually lanceolate or broader; plants when well developed tall and erect, somewhat Aster like 5 Rays mostly 2-4 mm wide; pappus mostly simple E. PEREGRINUS (Pursh) Greene 5 Rays mostly about 1 mm wide or less; pappus mostly double 6 Plants rather equably leafy, the upper leaves gradually reduced, the middle leaves commonly as large as or larger than the often deciduous lowermost ones E . SPECIOSUS Lindl . 6 Plants rather inequably leafy, the uppermost leaves strongly reduced, the middle ones commonly smaller than the mostly persistent lowermost ones E . GLABELLUS Nutt. 4 Cauline leaves usually much reduced, mostly linear or oblanceolate, broader in some low species; plants scarcely Asterlike, mostly relatively low, and often spreading 7 Leaves, or some of them, more or less lobed, divided, parted, or coarsely toothed E. COMPOSITUS Pursh 7 Leaves entire, or rarely slightly toothed 8 Involucre woolly-villous with multicellular hairs; monocephalous alpine and subalpine or artic plants E . SIMPLEX Greene 8 Involucre variously pubescent or glandular but not woolly-villous; habit and habitat various 213 9 Rays yellow, or shorter than the disk and inconspicuous, or lacking E. LINEARIS (Hook.) Piper 9 Rays evident, blue or purple to pink or white, not yellow 10 Cauline leaves relatively well developed, lanceolate to ovate or ovate-oblong E. CAESPITOSUS Nutt. 10 Cauline leaves mostly not very well developed, mostly linear or oblanceolate, sometimes narrowly lance- oblong, those of some species, while narrow, some- times not much smaller than the lowermost ones 11 Caudex with several or many slender, almost rhizo- matous branches, bearing numerous fibrous roots, and without a well defined taproot or long central axis; base of stem and bases of basal leaves con- spicuously purplish 12 Involucre glandular and spreading-hirsute E. URSINUS D.C.Eat. 12 Involucre strigose or strigose-hirsute with appressed or slightly loose hairs, scarcely or not at all glandular E. GRACILIS Rydb. 11 Caudex simple or more commonly with relatively stout (occasionally slender) branches, with few or no long fibrous roots (except in E. glabellus and E. peregrinus); plants with an evident taproot or stout central underground axis (except in E . glabellus) ; base of stem and bases of basal leaves purplish in only a few species, and these not with slender caudical branches 13 Plants with a simple or slightly branched caudex and numerous fibrous roots; stem erect; rays numerous, usually well over 100, about 1 mm wide E. GLABELLUS Nutt. 13 Plants with the caudex variously branched or simple, but without numerous fibrous roots except in E. peregrinus; stem and rays various 14 Pubescence of the stem appressed or ascending or wanting 15 Basal leaves usually triple-nerved; outer pappus setulose and obscure, or wanting E. EATONII A.Gray 15 Basal leaves not at all triple-nerved; outer pappus usually rather conspicuous, of scales or thick setae 214 16 Achenes 4- to 7-nerved E. PEREGRINUS (Pursh) Greene 16 Achenes 2-nerved E. TWEEDYI Canby 14 Pubescence of the stem widely spreading 17 Plants freely branched, mostly biennials or short- lived perennials, with disk corollas only about 2-3 mm long E . DIVERGENS T . & G . 17 Plants simple or sparingly branched (except in E . pumilus); true perennials often with a branched caudex; disk corollas over 3 mm long 18 Basal leaves in well developed plants evidently triple-nerved 19 Involucral bracts evidently thickened on the back; basal leaves usually rounded or obtuse at the tip; stem rarely purplish at the base E. CAESPITOSUS Nutt . 19 Involucral bracts only slightly or obscurely thickened on the back; basal leaves acute; stem ordinarily purplish at the base E. CORYMBOSUS Nutt. 18 Basal leaves not triple-nerved, or only very faintly so 20 Heads turbinate, solitary or sometimes 2; pubescence of the leaves short and fine; mountain plants E. RYDBERGII Cronq. 20 Heads hemispheric; leaves conspicuously pubescent with coarse spreading hairs; chiefly foothill and plains plants E. PUMILUS Nutt. Gnaphalium L . Cudweed; Everlasting 1 Heads small the involucre mostly 2-4 mm high; glomerules of heads leafy-bracted; plants rarely as much as 3 dm tall, usually much branched G . PALUSTRE Nutt. 1 Heads larger, the involucre mostly 4-7 mm high; glomerules not conspicuously leafy-bracted; plants mostly 2-9 dm tall, simple below the inflorescence or moderately branched 2 Annual or biennial; leaves merely adnate-auriculate G. CHILENSE Spreng. 2 Perennial; leaves narrowly decurrent G. MICROCEPHALUM Nutt. 215 Haplopappus Cass. Nom . Conserv. 1 Plants shrubby, low, branching, not at all cespitose 2 Rays uniformly wanting; twigs densely white-tomentose H. MACRONEMA Gray 2 Rays ordinarily present; twigs glandular to glabrous or occasionally gray-tomentose H. SUFFRUTICOSUS (Nutt.) Gi 1 Plants herbaceous , sometimes with a shortly aerial woody caudex, often densely cespitose; in any case the flowering stems herbaceous and of only a single year's duration 3 Plants more or less densely cespitose and generally mat-forming or cushion-forming, with a much branched caudex, numerous tufted basal leaves, and more or less numerous monocephalous stems rarely over 2 dm tall H. ACAULIS (Nutt.) Gray 3 Plants not densely cespitose and not at all mat-forming or cushion-forming, the caudex simple or moderately branched, the flowering stems several or solitary, leafy or sub-naked, with 1-many heads, often well over 2 dm tall 4 Heads characteristically solitary, occasionally with 1 or 2 lateral heads in robust plants 5 Involucre mostly 10-14 mm high, the disk corollas mostly 7-10 mm long H. INTEGRIFOLIUS Gray 5 Involucre 5-10 mm high, the disk corollas mostly 5-7 mm long H . UNIFLORUS (Hook . ) T . & G . 4 Heads characteristically several or numerous, occa- sionally solitary in depauperate plants H. LANCEOLATUS Hook. Helianthella T.& G. Involucral bracts ovate or lanceolate; rays pale yellow; receptacular bracts soft and scarious H. QUINQUENERVIS (Hook.) Gray Involucral bracts mostly lance-linear to sometimes linear-oblong; rays bright yellow; receptacular bracts firm H . UNIFLORA (Nutt . ) T . & G . 216 Helianthus L. Sunflower 1 Plants annual 2 Central receptacular bracts conspicuously white- bearded at the tip; involucral bracts lanceolate, taper- ing, not long-hairy, scarcely ciliate H. PETIOLARIS Nutt. 2 Central receptacular bracts inconspicuously hairy, not at all bearded; involucral bracts chiefly ovate or ovate-oblong and abruptly contracted above the middle, usually ciliate and with some long hairs on the back H. ANNUUS L. 1 Plants perennial H . NUTTALLII T.&G. Hieracium L. Hawkweed 1 Flowers yellow; stellate hairs always present on the involucre (though sometimes obscured by the longer bristles), often also on the stem and leaves 2 Leaves generally more or less long-hairy, at least marginally, the lower ones often well over 10 cm long; mostly rather stout plants, occurring in dry places, commonly 3-13 dm tall H. CYNOGLOSSODIES Arv.-Touv. 2 Leaves glabrous, or somtimes inconspicuously short- hairy, up to 10 (13) cm long; slender plants of moist places in the mts . mostly 0.3-3.5 dm tall H. GRACILE Hook. 1 Flowers white; stellate hairs wanting H. ALBIFLORUM Hook. Iva L . 1 Annual; leaves long-petiolate; inflorescence paniculiform , the heads not individually subtended by leaves I . XANTHIFOLIA Nutt . 1 Perennial from a creeping rootstock; leaves sessile or subpetiolate; heads axillary I. AXILLARIS Pursh 217 Lactuca L. Lettuce 1 Annual or biennial; heads relatively small, the fruiting involucre mostly 9—15 mm high; flowers yellow, often drying blue L. SERRIOLA L. 1 Perennial; heads relatively large and showy, the fruiting involucre 15-20 mm high; flowers blue L. PULCHELLA (Pursh) DC. Machaeranthera Ness 1 Annual with pinnately incised to tripinnatifid leaves M. TANACETIFOLIA (H.B.K.) Nees 1 Biennial or perennial with entire or merely toothed leaves M . CANESCENS (Pursh) Gray Microseris Don (Including Nothocalais) 1 Plants more or less caulescent, often branched and several- headed; pappus of 8-20 members, these chaffy at the base, tipped with a definite, slender awn M. NUTANS (Geyer) Shultz 1 Plants scapose, simple and monocephalous; pappus of 10- 80 very narrow, gradually attenuate scales or bristles or both, these not clearly divided into a chaffy base and awn tip (Nothocalais) 2 Leaves narrow, mostly 20-50 times as long as wide, the margins generally more or less crisped or wavy; invol- ucral bracts lanceolate or linear-lanceolate M. TROXIMOIDES Gray 2 Leaves broader, mostly 5-20 times as long as wide, the margins scarcely or not at all crisped or wavy; invol- ucral bracts ovate or broadly lanceolate; meadows and moist slopes M . NIGRESCENS Hend. 218 Senecio L. Groundsel; Ragwort; Butterweed 1 Cauline leaves well developed, only gradually reduced upwards; no well developed tuft of basal leaves present 2 Dwarf, freely branched; leaves about 4 cm long or less S . FREMONTII T.&G. 2 Taller, mostly 2-15 dm tall or more, the stem generally simple below the inflorescence; leaf blades mostly over 4 cm long 3 Cauline leaves, at least in part, sessile, with broad, more or less clasping base S. CRASSULUS Gray 3 Cauline leaves, except sometimes the reduced upper ones, petiolate, or tapering to a narrow, petioliform base 4 Leaves, at least the lower, triangular, with del- toid to cordate base S. TRIANGULARIS Hook. 4 Leaves all tapering to the base, not at all triangular S. SERRA Hook. 1 Cauline leaves generally strongly and progressively reduced upwards (or the stem sometimes scapose); basal or lower cauline leaves well developed, often tufted 5 Plants glabrous from the first, or sometimes lightly floccose-tomentose when young; if tomentose when young, then glabrous by flowering time except occa- sionally for a little inconspicuous tomentum at the base and in the leaf axils 6 Leaves entire or denticulate to sharply dentate, not at all pinnatifid, lobed, wavy, or crenate; plants, except sometimes S. crassulus, with the numerous fibrous roots arising from a very short, erect, short- lived crown, without any more elongate caudex or rhizome. (The glabrate extremes of several of the pubescent species might be sought here, except for the well developed rhizome or caudex.) 7 Heads few, seldom as many as a dozen, apparently always radiate; plants of dry to moderately moist habitats S. CRASSULUS Gray 7 Heads more numerous, seldom less than a dozen in well developed plants, often very numerous, radiate or more often discoid; plants mostly of wet places S . HYDROPHILUS Nutt. 219 6 Leaves, or some of them, pinnatifid, lyrate, crenate, or wavy; plants with a more evident, longer-lived and more woody, ascending or horizontal caudex or rhizome 8 Heads solitary or rarely 2; alpine to subalpine plants, to 3 dm tall S. CYMBALARIOIDES Buck. 8 Heads generally several 9 Basal leaves, or some of them, cordate or subcor- date, sharply toothed; cauline leaves laciniate- pinnatifid, at least toward their bases; leaves thin S. PSEUDAUREUS Rydb . 9 Basal leaves not cordate or subcordate, though sometimes subrotund 10 Leaves relatively thin and lax, the basal ones mostly elliptic or oblanceolate , crenate or serrate to subentire S. PAUPERCULUS Michx. 10 Leaves relatively thick and firm, the basal ones mostly elliptic to subrotund, coarsely crenate to shallowly lobulate or subentire 11 Cauline leaves well developed, the middle and lower clasping and as large as or even larger than the basal ones; basal leaves generally broadly ovate to orbicular or subreniform , 1-1.5 times as long as wide; alpine and sub- alpine meadows and rocky slopes S. DIMORPHOPHYLLUS Greene 11 Cauline leaves progressively reduced, not clasping; basal leaves generally elliptic to ovate or subrotund, typically about twice as long as wide; woods and moist to mod- erately dry open places at mid to high elev- ations S . STREPTANTHIFOLIUS Greene Plants more or less pubescent at flowering time 12 Pubescence loosely crisp-villous or arachnoid- villous , sometimes very sparse by flowering time; plants with numerous fibrous roots arising from a very short, erect, short-lived crown, without a more elongate caudex or rhizome S. INTEGERRIMUS Nutt. 12 Pubescence finer, more tomentose or floccose; plants with an evident, more or less woody, ascend- ing or horizontal caudex or short rhizome 220 13 Leaves sharply dentate (with divergent teeth) to merely callous-denticulate or even (in forms S . sphaerocephalus) entire; plants with the stems mostly arising singly from a short, horizontal rhizome 14 Involucral bracts with minute black or brownish tips, mostly about 21, rarely only 13; plants of moderate elevations in and near the mts . S. SPHAEROCEPHALUS Greene 14 Involucral bracts with very conspicuous black tips, commonly about 13, rarely up to 21 S. LUGENS Rich. 13 Leaves entire to crenate, crenate-serrate , or more or less lobed or pinnatifid; plants generally with several stems arising from a branched caudex, which may sur- mount a taproot S . CANUS Hook . Solidago L. Goldenrod 1 Plants with well developed creeping rhizomes; stem varying from densely and rather equably leafy, without well developed basal leaves (in most species) to some- times more sparsely and inequably leafy, with enlarged lower and basal leaves (in forms of S. missouriensis) 2 Stem glabrous below the inflorescence; leaf surfaces nearly always glabrous 3 Stem glaucous, becoming definitely puberulent in the inflorescence; plants 0.5-2 m tall; rays mostly about 13 (10-17); leaves numerous and equably distributed S. GIGANTEA Ait. 3 Stem glabrous or very nearly so throughout, not glaucous; plants mostly 2-9 dm tall; rays typically about 8, rarely 13; habit varying from that of the S . multiradiata group to nearly that of S. gigantea and S. canadensis S . MISSOURIENSIS Nutt . 2 Stem puberulent, at least above the middle; leaves puberulent to subglabrous S. CANADENSIS L. 1 Plants with mostly short and stout rhizomes, or a mere caudex; stem rather inequably leafy, the basal or lower cauline leaves larger and differently shaped than those above, tending to be persistent, the cauline leaves conspicuously reduced upwards and not very numerous 221 4 Leaves densely and finely canescent with short spread- ing hairs 5 Inflorescence either with more or less secund branches, or elongate and nodding at the tip; disk flowers mostly 5-9, about as many as or mostly fewer than the rays S . NEMORALIS Ait. 5 Inflorescence corymbiform and usually relatively broad, neither nodding at the tip nor with evidently secund branches; disk flowers mostly 8-16, ordinarily more numerous than the rays S. NANA Nutt. 4 Leaves glabrous except for the sometimes ciliate margins S . MULTIRADIATA Ait. Stephanomeria Nutt. Rush Pink; Skeletonweed 1 Plants low, mostly 1-2 dm tall, with the principal leaves evidently runcinate-pinnatifid; achenes pitted and tuber- culate S. RUNCIANTA Nutt. 1 Plants taller, commonly 2-7 dm tall, with linear or filiform, entire or toothed leaves; achenes smooth or very nearly so (except for being longitudinally ribbed) S . TENUIFOLIA (Torr . ) Hall Taraxacum Hall. Dandelion 1 Introduced, weedy species 2 Achenes becoming red to reddish brown or reddish purple at maturity, the beak mostly 1-3 times as long as the body; leaves tending to be deeply cut for their whole length, without an enlarged terminal segment, the lobes narrow; outer involucral bracts appressed to loose or sometimes reflexed; inner involucral bracts commonly corniculate T. LAEVIGATUM (Willd.)DC. 2 Achenes olivaceous or stramineous to brown, the beak mostly 2.5-4 times as long as the body; leaves usually less deeply cut, often with an enlarged terminal lobe; outer involucral bracts reflexed; inner involucral bracts not corniculate T . OFFICINALE Weber 1 Native, unaggressive species of the high mts . ; leaves less dissected than in T. laevigatum; outer involucral bracts appressed to lax or somewhat spreading, not reflexed T. CERATOPHORUM (Ledeb.) DC 222 Townsendia Hook. Daisy 1 Plants annual, biennial, or short-lived perennials with a mere crown, commonly several-stemmed from the base (the stems leafy) , seldom less than 5 cm high T. PARRYI Eat. 1 Plants cespitose perennials, the taproot surmounted by an evident branching caudex; acaulescent plants, seldom more than 5 cm high 2 Achenes glabrous or very nearly so; herbage sparsely strigose or glabrate; rays blue or violet; montane 3 Involucral bracts broadly lanceolate to ovate or elliptic, obtuse or acute T. MONTANA Jones 3 Involucral bracts linear to lanceolate, strongly acute; morphologically approaching T . montana T. LEPTOTES (Gray) Osterh. 2 Achenes persistently hairy, at least toward the base; herbage rather sparsely to densely strigose; rays white or pinkish; lower elevations T. EXSCAPA (Rich.) Porter Tragopogon L. Goatsbeard 1 Peduncles not enlarged in flower, scarcely so in fruit; achenes mostly 15-25 mm long (including the beak); flowers wholly yellow, the outer ligules equaling or sur- passing the involucral bracts; involucral bracts mostly about 8; leaves obscurely floccose at first, soon glabrate, with cirrhose-recurved tip; widespread diploid weed T . PRATENSIS L . 1 Peduncles enlarged and fistulous above in flower and fruit; achenes mostly 25-40 mm long; flowers yellow or purple, the ligules slightly to very much shorter than the involucral bracts; leaves not cirrhose-recurved at the tip; involucral bracts and pubescence various 2 Heads yellow, or with a yellow eye; involucral bracts commonly about 13, or only 8 on last-formed heads or on depauperate plants T. DUBIUS Scop. 2 Heads wholly purple; involucral bracts commonly about 8; ligules slightly to much shorter than the involucral bracts; leaves glabrous T. PORRIFOLIUS L. 223 Wyethia Nutt, 1 Herbage and involucre entirely glabrous, resinous- varnished; rays yellow W . AMPLEXICAULIS Nutt. 1 Herbage more or less pubescent, not resinous-varnished involucral bracts conspicuously ciliate W. HELIANTHOIDES Nutt. 224 INDEX AND COMMON NAMES Abies (PINACE) lasiocarpa Subalpine, balsam or white balsam fir Abronia (NYCTAG) fragrans Fragrant white abronia Acer (ACERAC) glabrum Rocky Mt. maple Achillea (COMPOS) millefolium Yarrow Aconitum (RANUNC) columbianum Columbian monkshood Actaea (RANUNC) rubra Western red baneberry Adoxa (ADOXAC) moschatellina Moschatel, musk-root, hollow-r Agastache (LABIAT) urticifolia Nettle-leaf horse-mint, giant-hyssop Agoseris (COMPOS) aurantiaca Orange agoseris glauca Pale agoseris Agropyron (GRAMIN) wheatgrass caninum Awned or bearded w. cristatum Crested w. dasystachyum Thick-spiked w. , downy w. repens Quack, quitch or couch grass schribneri Spreading w. smithii Bluestemw. spicatum Bluebunchw. triticeum Annual w . Agrostis (GRAMIN) bentgrass Page No 38 26 alba Creeping b. exarata Spike b . humilis Alpine b. idahoensis Idaho b. rossiae Ross' b. scabra Winter b. , rough hair-grass tickle-grass thurberiana Thurber b . 14 196 111 111 25 179 202 64 65 225 Allium (LILIAC) onion 84 brandegei Brandegee o. brevistylum Short-style o. cernuum Nodding o. geyeri Geyer's o. schoenoprasum Chives textile Textile o. Alnus (BETULA) 95 incana Mountain alder sinuata Wavy-leaved alder Alopecurus (GRAMIN) foxtail 66 aequalis Shortawn f . , Little-meadow f . alpinus Alpine f. Alyssum (CRUCIF) 120 alyssoides Pale alyssum Amaranthus (AMARAN) pigweed 105 albus Tumbleweed, white p . retroflexus Rough p. , p. amaranth, redroot a. Amelanchier (ROSACE) 137 alnifolia Western serviceberry Anaphalis (COMPOS) 199 margaritacea Common pearly-everlasting Androsace (PRIMUL) fairy-candelabra 168 filiformis Slender-stemmed f . -c . lehmanniana Sweet-flowered androsace septentrionalis Northern f. -c . Anemone (RANUNC) anemone 112 multifida Pacific a., cliff a. nuttalliana Pasqueflower, wild crocus, lionsbeard Angelica (UMBELL) angelica 163 arguta Sharptooth a. , Lyall's a. pinnata Pinnate-leaved a. Antennaria (COMPOS) pussy-toes 203 alpina Alpine p . anaphaloides Tall p. corymbosa Meadow p . , flat-topped p . dimorpha Low p . lanata Wooly p . luzuloides Woodrush p . microphylla Rosy p . parvifolia Nuttall's p. racemosa Raceme p. umbrinella Umber p. 226 Apocynum (APOCYN) dogbane 170 androsaemifolium Spreading d., flytrap d. cannabinum Common d. , hemp d. medium Western d. sibiricum Clasping-leaved d., Indian hemp Aquilegia (RANUNC) columbine 112 coerulea Colorado c . flavescens Yellow c . Arabis (CRUCIF) rockcress 124 davaricarpa Spreadingpod r . drummondii Drummond'sr. fructicosa Yellowstone r . glabra Towermustard hirsuta Hairy r . holboellii Holboell'sr. lemmonii Lemmon'sr. lignifera Woody-branch r . lyallii Lyall's r . microphylla Littleleaf r . nuttallii Nuttall's r. sparsiflora Elegant r . , sicklepod r. Arceuthobium (LORANT) dwarf mistletoe 96 americanum American d. m. campylopodum Western d. m. Arctostaphylos (ERICAC) 166 uva-ursi Kennikinnick , bearberry, sandberry Arenaria (CARYOP) sandwort 108 congesta Capitate s., ballhead s. lateriflora Bluntleaf s. obtusiloba Arties. Arnica (COMPOS) arnica 204 chamissonis cordifolia diversifolia fulgens latifolia longifolia mollis parryi rydbergii sororia Leafy a. , meadow a. Heart-leafed a . Sticky a . Orange a. , hillside a. Mountain a . Seep-spring a . Hairy a . Nodding a . Rydber.g's a. , subalpine a Twin a . 227 Artemisia (COMPOS) sagebrush arbuscula Low s. , dwarf s. biennis Biennial wormwood campestris Northern wormwood cana Silver s . , hoary s . dracunculus Tarragon, dragon sagewort frigida Pasture s. , fringed s. ludoviciana Western mugwort, prairie sage michauxiana Michaux mugwort scopulorum Rocky Mountain s. tridentata Big s . tripartita Threetip s., cut-leafs. vulgaris Mugwort Asclepias (ASCLEP) milkweed speciosa Showy m. , Greek m. Aster (COMPOS) aster alpigenus Alpine a . alpinus Boreal a. brachyactis Rayless alkali a . chilensis Ascending a. conspicuus Showy a. eatonii Eaton's a. engelmannii Engelmann's a . falcatus Little gray a. , creeping white prairie a . foliaceus Leafy a. , leafy-bract a. glaucodes Dusty a. hesperius Western willow a. , marsh a. integrifolius Thick-stemmed a . , entire- leaved a . occidentalis Western mountain a . perelegans Elegant a. scopulorum Crag a. , lava a. sibiricus Arctic a. Astragalus (LEGUMI) milk-vetch 205 18 207 144 aboriginum agrestis alpinus americanus canadensis cibarius drummondii eucosmus kentrophyta Indian m . Field m . , purple m . Alpine m . , purple m . American m . , arctic m Canada m . Browse m . Drummond's m. Elegant m . Thistle m . 228 Astragalus, continued miser Weedy m . purshii Woollypod m. , Pursh's m . tenellus Pulse m. vexilliflexus Bent-flowered m . Athyrium (POLYPO) 36 felix-femina Lady-fern Atriplex (CHENOP) 103 argentea Silverscale canescens Wingscale, fourwing saltbush, hoary saltbush gardneri Saltsage, moundscale hortensis Orache, garden o. , sea purslane rosea Red orache truncata Wedgescale orache Balsamorhiza (COMPOS) 194 sagittata Arrowleaf balsamroot Barbarea (CRUCIF) 121 orthoceras American wintercress Beckmannia (GRAMIN) 58 syzigachne Slough grass Berula (UMBELL) 160 erecta Cut-leaved water-parsnip , stalky berula Besseya (SCROPH) 181 wyomingensis Wyoming besseya Betula (BETULA) birch 96 glaudulosa Bog b. , scrub b. occidentalis Water b. , spring b. , red b. Bidens (COMPOS) 193 cernua Nodding beggar-ticks, sticktight Botrychium (OPHIOG) 2 multifidum Leathery grape-fern Bouteloua (GRAMIN) 57, 58 gracilis Blue grama Brassica (CRUCIF) mustard 126 campestris Field m . , common m . kaber Charlock, wild m . Brickellia (COMPOS) 199 grandiflora Large-flowered brickellbush, thoroughwort Bromus (GRAMIN) 67 anomalus Nodding brome brizaeformis Rattle grass, rattlesnake g. carinatus California brome 229 Bromus (GRAMIN) continued ciliatus Fringed brome inermis Smooth or Hungarian brome tectorum Cheat grass, downy c . Bupleurum (UMBELL) 160 americanum American thorough-wax Calamagrostis (GRAMIN) reedgrass 68 canadensis Bluejointr. inexpansa Narrow-spiked r . koelerioides Fire r . purpurascens Purple r., pinegrass rubescens Pinegrass Calochortus (LILIAC) mariposa 84 eurycarpus Wide-fruit m . , big-pod m. gunnisonii Gunnison's m . , sego-lily Caltha (RANUNC) marshmarigold 112 leptosepala Elkslip, eastern m . Calypso (ORCHID) 86 bulbosa Fairy-slipper, venus slipper Camassia (LILIAC) 83 quamash Common camas Camelina (CRUCIF) falseflax 126 microcarpa Littlepod f . sativa F . , gold-of-pleasure Campanula (CAMPAN) bellflower 192 rotundifolia Harebell, lady ' s-thimble Capsella (CRUCIF) 121 bursa-pastoris Sherpherd's purse Cardamine (CRUCIF) bittercress 126 breweri Brewer's b. cordifolia Large mt. b. oligosperma Little western b . Cardaria (CRUCIF) 121 pubescens Globepodded hoarycress Carduus (COMPOS) 198 nutans Musk thistle Carex (CYPERA) sedge 46 albonigra Black-and-white scaled s. angustior Muricates. aquatilis Water s . athrostachya Slenderbeaked s . aurea Golden s. , golden-fruited s. brevior Short -beaked s . brevipes Short-stalked s . 230 Carex (CYPERA) continued buxbaumii canescens concinna diandra disperma douglasii festivella geyeri hallii hassei heliophila heteroneura hoodii illota interior kelloggii lanuginosa leporinella limnophila luzulina microptera nebraskensis neurophora paysonis petasata phaeocephala platylepsis praegracilis praticola raynoldsii rossii rostrata spectabilis stenoptila vallicola vesicaria v-iridula xerantica Carum (UMBELL) carvi Caraway Castilleja (SCROPH) paintbrush cusickii Cusick'sp. exilis Annual p . Buxbaum's s. Gray s . Low northern s. Lesser panicled s. Short-leaved s . Douglas1 s. Bright s . Elk s . , Geyer 's s . Hall's s. Hasse' s s . Sun-loving s . Darkened s . Hood's s. Sheep s. , small-headed s, Inland s . Kellogg's s . Woolly s . Sierra-hare s . Pond s . Woodrush s . Small-winged s. Nebraska s . Alp nerved s . Payson s . Liddon' s s . Dunhead s . , mt . hare s . Broad-scaled s . Clustered field s. Meadow s . Raynolds1 s. Ross s. Beaked s . Showy s . Narrow-winged s. Valley s . Inflated s . Greenish s . Dryland s . 161 181 231 Castilleja (SCROPH) continued graciliima Slender p . linariaefolia Wyoming p. longispica White p . miniata Scarlet p., common p . pallescens Palish Indian-p . pulchella Showy Indian-p . rhexifolia Rhexia-leaved p . sulphurea Sulfur p . Ceanothus (RHAMNA) 151 velutinus Mt. balm, sticky-laurel greasewood Centaurea (COMPOS) 198 maculosa Spotted knapweed Cerastium (CARYOP) 108 arvense Field chickweed vulgatum Common c . , big c . , mouse-ear c . Ceratophyllum (CERATO) 11 demersum Hornwort, coontail Chaenactis (COMPOS) 210 alpina Alpine chaenactis douglassii Hoary c . , false-yarrow Chenopodium (CHENOP) goosefoot 104 album Lambsquarter , white g., pigweed capitatum Strawberry blite fremontii Fremont's g. glaucum Glaucous g. , oakleaf g. hians Gaping g . leptophyllum Slimleafg. rubrum Red g . Chimaphila (ERICAC) pipsissewa 166 umbellata Prince' s-pine , common p . Chrysanthemum (COMPOS) 197 leucanthemum Marguerite, oxeye-daisy moon-daisy Chrysopsis (COMPOS) 196 villosa Hairy goldenaster Chrysothamnus (COMPOS) rabbit-brush 210 nauseosus Common r. , gray r. parryi Parry's r. viscidiflorus Green r. Cicuta (UMBELL) 160 douglasii Western water-hemlock, Douglas' w. 232 Cinna (GRAMIN) 61 latifolia Woodreed, wood reed-grass Cirsium (COMPOS) thistle 210 arvense Canada t., creeping t. flodmanii Flodman's t. foliosum Leafy t . scariosum Elk t., Everts t. subniveum Jackson's Hole t. tweedyi Tweedy'st. undulatum Wavy-leaved t. vulgare Common t. , bull t., spear t. Claytonia (PORTUL) springbeauty 106 lanceolata Western s. , lanceleaf s. Clematis (RANUNC) clematis 112 columbiana Columbia c . , rock c . hirsutissima Sugarbowls, vaseflower, Douglas1 c . ligusticifolia Western c . , virgins-bower Cleome (CAPPAR) 22 serrulata Rocky Mt. bee plant, stinkweed Collomia (POLEMO) 171 linearis Narrow-leaf collomia Collinsia (SCROPH) 181 parviflora Small-flowered blue-eyed mary Comandra (SANTAL) 28 umbellata Bastard toad-flax Conimitella (SAXIFR) 132 williamsii Conimitella Convolvulus (CONVOL) morning-glory 33 arvensis Field m . , small bindweed Conyza (COMPOS) 196 canadensis Horseweed, Canada fleabane Corallorhiza (ORCHID) coral-root 87 maculata Pacific c. , spotted c. mertensiana Western c . striata Hooded c . , striped c . trifida Early c . , yellow c . wisteriana Wister c . Cornus (CORNAC) 165 canadensis Bunchberry, puddingberry , dwarf cornel stolonifera Creek dogwood, red-osier d. Corydalis (FUMARI) corydalis 119 aurea Golden c . , golden smoke 233 Crepis (COMPOS) hawksbeard acuminata Long-leaved h. , tapertip h atrabarba Slender h. elegans Elegant h modocensis Low h. , Siskiyou h. occidentalis Western h. runcinata Dandelion h. , meadow h. tectorum Annual h. , rooftop h. Cryptantha (BORGI) crypthantha ambigua Obscure c . feldleri Fendler'sc. interrupta Bristly c . patter sonii Patterson's c . torreyana Torrey'sc. watsonii Watson's c. Cryptogramma (POLYPO) crispa Rock-brake, parsley-fern Cymopteris (UMBELL) terebinthinus Turpentine cymopterus longipes Long-stemmed cymopterus Cynoglossum (BORAGI) officinale Common Hound' s-tongue Cystopteris (POLYPO) fragilis Brittle bladder-fern Danthonia (GRAMIN) danthonia, oatgrass californica Cal. d., Cal . o. intermedia Timber d. , timber o. spicata Poverty d. , common wild o unispicata Onespike d., few-flowered Delphinium (RANUNC) larkspur bicolor Montana 1 . , little 1 . brownii Brown's 1. burkei Burke's 1. , meadow 1. glaucescens Palish 1. glaucum Pale 1 . nuttallianum Upland 1 . occidentale Western 1., duncecapl. Deschampsia (GRAMIN) caespitosa Tufted hairgrass elongata Slender hairgrass Descurainia (CRUCIF) pinnata Western tansymustard richardsonii Mt. tansymustard sophia Flixweed 234 Dicentra (FUMARI) 119 uniflora Steer's head Disporum (LILIAC) 83 trachycarpum Wartberry fairy-bell, Sierra f. Distichlis (GRAMIN) 57 stricta Alkali saltgrass Dodecatheon (PRIMUL) shooting star 169 conjugens Slimpod s. , desert s. pulchellum Few-flowered s . Douglasia (PRIMUL) 168 montana Rocky Mt. douglasia Draba (CRUCIF) draba 127 aurea Golden d . crassifolia Thickleaved d . densifolia Nuttall's d. fladnizensis Austrian whitlow-grass incerta Yellowstone d . nemorosa Wood's draba oligosperma Few-seeded d. paysonii Payson's d. praealta Tall d. stenoloba Slender d. ventosa Wind River d. Dracocephalum (LABIAT) 179 parviflora American dragonhead Drosera (DROSER) 6 anglica Great sundew Dryas (ROSACE) 137 octopetala White dryad Elaeagnus (ELAEAG) 157 commutata Silverberry, Wolf-willow Elatine (ELATIN) 12 triandra Three-stamen waterwort Eleocharis (CYPERA) spike-rush 53 acicularis Needles. flavescens Yellow s. palustris Common or creeping s. pauciflora Few-flowered s . rostellata Beaked s . Elodea (HYDROC) 5 canadensis Elodea, Rocky Mt. waterweed Elymus (GRAMIN) wildrye 70 canadensis Canada w . , nodding w . cinereus Giant w . glaucus Blue w. , western rye-grass 235 Epilobium (ONOGRA) willow-herb 158 alpinum angustifolium glaberrimum glandulosum latifolium palustre paniculatum suffruticosum watsonii Equisetum (EQUISE) horsetail arvense Common h. Alpine w . Fireweed, blooming Sally- Smooth w . Common w . Red w. Swamp w . , Autumn w . Shrubby w Watson's w wickup tall annual w 35 field h. fluviatile Water h. hyemale Dutch rush, common scouring-rush laevigatum Smooth scouring-rush variegatum Northern scouring-rush, variegated h. Erigeron (COMPOS) fleabane, daisy 212 acris Bitter f . caespitosus Gray d. , tufted f . compositus Cut-leafed d . , dwarf mt. f. corymbosus Long-leaf f. , foothill d. divergens Diffuse or spreading f . eatonii Eaton's d. glabellus Smooth d. gracilis Slender f. linearis Line-leaf f. , desert yellow d. lonchophyllus Spear-leaf f. , short-rayed d . peregrinus Subalpine d. , wandering d. or f . pumilus Shaggy f . rydbergii Rydberg's d. simplex Alpine d. , one-stemmed f. speciosus Showy f . strigosus Daisy f. , branching d. tweedyi Tweedy 'sd. ur sinus Bear River f . Eriogonum (POLYGO) buckwheat caespitosum Matb. flavum Yellow b . heracleoides Wyeth b . , parsnip-flowered eriogonum ovalifolium Cushion b . , oval-leaved e . umbellatum Sulfurflower , sulfur b. 97 236 Eriophorum (CYPERA) 54 chamissonis Chamisso's cotton-grass polystachion Many-spiked cotton-grass viridicarinatum Green keeled cotton-grass Eriophyllum (COMPOS) 194 lanatum Eriophyllum Er odium (GERANI) 153 cicutarium Crane's-bill, stork1 s-bill Erysimum (CRUCIF) 129 asperum Rough wallflower, prairie rocket cheiranthoides Treacle mustard, wormseedm. inconspicuum Smallflowered rocket, small w. Erythronium (LILIAC) 83 grandiflorum Pale fawn-lily, dogtooth violet glacier lily Euphorbia (EUPHOR) 153 glyptosperma Corrugate-seeded spurge serpyllifolia Thyme-leaf spurge Eurotia (CHENOP) 101 lanata Winterfat, white sage Festuca (GRAMIN) fescue 70 idahoensis Blue bunchgrass, Idaho f. occidentalis Western f . ovina Sheep f . rubra Red f . Floerkea (LIMNAN) 24 proserpinacoides False-mermaid Foeniculum (UMBELL) 161 vulgare Sweet fennel Fragaria (ROSACE) 139 vesca Woods strawberry virginiana Wild strawberry Frasera (GENTIA) 169 speciosa Giant frasera Frittillaria (LILIAC) 85 atropurpurea Checker lily, chocolate lily pudica yellow bell, fritillary Gaillardia (COMPOS) 193 aristata Blanket-flower Galeopsis (LABIAT) 179 ladanum Hemp nettle Galium (RUBIAC) bedstraw 189 aparine Goose-grass bifolium Thinleafb., low mt . b. 237 Galium (RUBIAC) continued boreale Northern bedstraw trifidum Sweetscented b . , fragrant b . Gaultheria (ERICAC) wintergreen 165 humifusa Alpine w. , western w. , matted w. Gaura (ONOGRA) 157 parviflora Small-flowered gaura Gayophytum (ONOGRA) 159 humile Dwarf groundsmoke ramosissimum Hairstem groundsmoke Gentiana (GENTIA) gentian 169 affinis Pleated g., prairie g. algida Whitish g . amarella Northern g. detonsa Small fringed g. Geranium (GERANI) geranium 153 bicknellii Bicknell'sg. richardsonii White g . , sticky g . viscosissimum Sticky purple g. Geum (ROSACE) avens I39 aleppicum Yellow a. macrophyllum Large-leaved a. rossii Ross' a. triflorum Prairie smoke a . , old mans whiskers Gilia (POLEMO) 172 aggregata Scarlet gilia, skyrocket tenerrima Delicate gilia Glaux (PRIMUL) 168 maritima Saltwort, sea-milkwort Glecoma (LABIAT) I79 hederacea Gill-over-the-ground, field balm, creeping Charlie Glyceria (GRAMIN) 71 borealis Northern mannagrass elata Tall mannagrass striata Fowl mannagrass Glycyrrhiza (LEGUMI) I43 lepidota American licorice Gnaphalium (COMPOS) 215 chilense Cotton-batting plant microcephalum Slender cudweed, white c. palustre Lowland cudweed 238 Goodyera (ORCHID) 86 oblongifolia Western rattlesnake-plantain, Giant r . Grayia (CHENOP) 102 spinosa Spiny hopsage Grindelia (COMPOS) 200 squarrosa Resin-weed, curly-cup gumweed Gutierrezia (COMPOS) 195 sarothrae Broom snakeweed Gymnosteris (POLEMO) 171 parvula Small-flowered gymnosteris Habenaria (ORCHID) bog-orchid, rein-orchid 87 dilatata White b. , leafy white orchis hyperborea Northern green b. obtusata Blunt-leaf r . , one-leaf r . saccata Slender b. unalascensis Alaska r. Hackelia (BORAGI) 177 floribunda Many-flowered stickseed micrantha Blue stickseed patens Spreading stickseed Haplopappus (COMPOS) goldenweed 216 acaulis Stemlessg. integrifolius Entire-leaved g . lanceolatus Lance-leaf g. macronema Discoid g. suffruticosus Shrubby g., big-head g. uniflorus One-flowered g . Hedysarum (LEGUMI) 149 boreale Northern hedysarum sulphurescens Yellow hedysarum Helianthella (COMPOS) 216 quinquenervis Nodding helianthella uniflora Rocky Mt. helianthella Helianthus (COMPOS) 217 annuus Common sunflower nuttalli Nuttall's sunflower petiolaris Prairie sunflower Heracleum (UMBELL) 160 lanatum Cow-parsnip Hesperochiron (HYDROP) 174 pumilus Dwarf hesperochiron Hesperochloa (GRAMIN) 63 kingii Spike-fescue 239 Heuchera (SAXIFR) alumroot 133 cylindrica Roundleaf a. , lava a. parvifolia Common a . , small-leaved a . Hieracium (COMPOS) hawkweed 217 albiflorum White-flowered h. cynoglossoides Hounds-tongue h. gracile Slender h. , alpine h. Hierochloe (GRAMIN) 56, 59 odorata Sweetgrass, vanillagrass, holy grass Hippuris (HIPPUR) 11 vulgaris Common mare's-tail Hordeum (GRAMIN) 71 brachyantherum Meadow barley jubatum Squirrel-tail, foxtail barley pusillum Little barley Horkelia (ROSACE) 138 fusca Horkelia Hulsea (COMPOS) 195 algida Alpine hulsea Hydrophyllum (HYDROP) 174 capitatum Ballhead waterleaf , wool breeches Hyoscyamus (SOLANA) 180 niger Black henbane, hog's bean Hypericum (HYPERI) 154 formosum Western St. John's-wort perforatum Common St. John's-wort Hypopitys (ERICAC) 165 monotropa Fringed pinesap Iliamna (MALVAC) 154 rivularis Streambank globemallow Iris (IRIDAC) 85 missouriensis Western blue fleur-de-lis Isoetes (ISOETA) 35 bolanderi Bolander's quillwort lacustris Lake quillwort Iva (COMPOS) 217 axillaris Poverty-weed, deep-root xanthifolia Tall marsh-elder Iversia (ROSACE) 138 gordonii Gordon's iversia Juncus (JUNCAC) rush 42 balticus Baltic r. drummondii Drummond'sr. 240 Juncus (JUNCAC) continued ensifolius Dagger-leaf r . hallii Hall's r. longistylis Long-styled r . mertensianus Merten'sr. nevadensis Sierra r. parryi Parry's r. regelii Regel'sr. tenuis Slender r. torreyi Torry'sr. tracyi Tracy's r . tweedyi Tweedy'sr. Juniperus (CUPRES) 38 communis Common or mt. juniper scopulorum Rocky Mt. juniper Kalmia (ERICAC) 166 microphylla Small-leaved or alpine laurel Kelloggia (RUBIAC) 189 galoides Kelloggia Kochia (CHENOP) burning-bush 102 scoparia Summer or mock cypress, b. Koeleria (GRAMIN) Junegrass 62, 63 cristata Prairie j . , Koeler's grass Lactuca (COMPOS) 218 pulchella Blue lettuce serriola Prickly lettuce Laminum (LABIAT) 179 amplexicaule Common dead-nettle , henbit Lappula (BORAGI) 175 redowskii Western stickseed Ledum (ERICAC) labrador-tea 166 glandulosum Trapper's t., smooth 1., mt. 1. Lemna (LAMNAC) duckweed 82 minima Least d. minor Water lentil trisulca Star d. , ivy d. Lepidium (CRUCIF) pepper grass 129 densiflorum Prairie p. , common p. perfoliatum Clasping p. ramosissimum Branched p . virginicum Tall p . Leptodactylon (POLEMO) 171 pungens Prickly phlox 241 Lesquerella (CRUCIF) 119, 120, 121 alpina Alpine bladderpod Lewisia (PORTUL) 106 pygmaea Least, dwarf, alpine lewisia rediviva Bitterroot triphylla Threeleaf lewisia Ligusticum (UMBELL) 163 1 canbyi Canby's licorice-root filicinum Fern-leaf licorice-root porteri Porter licorice-root Linathus (POLEMO) 171 septentrionalis Northern linanthus Linaria (SCROPH) 183 dalmatica Dalmatian toadflax vulgaris Butter and eggs Linnaea (CAPRIF) 190 borealis Twinflower Linum (LINACE) 31 perenne Blue flax Listera (ORCHID) twayblade 89 caurina Western t. cordata Heart-leaf listera, t. Lithophragma (SAXIFR) fringecup 133 bulbifera Bulbiferous f . , prairiestar parviflora Smallflower f . , woodlandstar tenella Slender f., prairiestar Lithospermum (BORAGI) gromwell 177 incisum Yellow g. ruderale Western g., Columbia puccoon Lolium (GRAMIN) 59 perenne English ryegrass Lomatium (UMBELL) desert-parsley 163 ambiguum Swale d . cous Cous, Cous biscuit-root dissectum Fern-leaved lomatium or d . macrocarpum Large-fruit d . nudicaule Bare-stem lomatium, pestle parsnip triternatum Nine -leaf lomatium Lonicera (CAPRIF) honeysuckle 190 caerulea Sweet-berry h. , bluefly h. involucrata Bearberry h. , black twin-berry utahensis Utah h. 242 Lupinus (LEGUMI) lupine 150 argenteus Slivery 1. caudatus Tailcup 1., Kellogg spurred 1. lepidus Prairie 1. polyphyllus Bigleafl., many-leaved 1 . sericeus Silky 1 . wyethii Wyeth'sl. Luzula (JUNCAC) woodrush 44 campestris Field w. , Sweep's brush parviflora Smallflowered w . piperi Piper's w. spicata Spiked w . Lychnis (CARYOP) campion 108 alba White c . , evening c . drummondii Drummond c . Lycopodium (LYCOPO) clubmoss 1 annotinum Interrupted c . , stiff c . Lycopus (LABIAT) 178 americanus Cut-leaved water horehound Machaeranthera (COMPOS) 218 canescens Hoary aster tanacetifolia Tansy aster Madia (COMPOS) 195, 200 glomerata Cluster tarweed, mt. t. Mahonia (BERBER) Oregongrape 12, 16 repens Creeping O . , low O . Matricaria (COMPOS) 197, 201 matricarioides Pineapple weed Medicago (LEGUMI) 151 lupulina Black medic, hop clover sativa Alfalfa, lucerne Melica (GRAMIN) 72 bulbosa Oniongrass smithii Smith's melic spectabilis Showy oniongrass subulata Alaska oniongrass Meliotus (LEGUMI) 151 alba White sweet-clover officinalis Yellow sweet-clover Mentha (LABIAT) 178 arvensis Corn mint, field mint Mentzelia (LOASAC) mentzelia 156 albicaulis White-stemmed m . , small flowered m . 243 Mentzelia (LOASAC) mentzelia continued decapetala Sand lily, evening star dispersa Bushy m . , small-flowered m . laevicaulis Blazing-star m . Menyanthes (MENYAN) 11 trifoliata Buckbean, bogbean Mertensia (BORAGI) bluebells 178 alpina Alpine b. ciliata Ciliate b. , Broad-leafed b. oblongifolia Leafy b . viridis Green b . Microseris (COMPOS) 218 nigrescens Black-hairy microseris nutans Nodding microseris troximoides False-agoseris Microsteris (POLEMO) 171 gracilis Pink microteris Mimulus (SCROPH) monkey-flower 183 breweri Brewer's m. floribundus Purple stem m . guttatus Yellow m. lewisii Lewis' m. moschatus Musk-flower, musk-plant nanus Dwarf purple m . suksdorfii Suksdorf'sm. tilingii Large m . Mitella (SAXIFR) miterwort 132 pentandra Alpine m . , five-stamened m . Monarda (LABIAT) 178 fistulosa Wild bergamont Monolepis (CHENOP) 102 nuttaliana Povertyweed, patata Montia (PORTUL) montia 106 chamissoi Chamisso's m. , water m. linearis Narrowleaved m . Muhlenbergia (GRAMIN) muhly 72 andina Foxtail m . , hairy m . asperifolia Alkli m. , rough-leaved dropseed filiformis Pullup m . , slender m . richardsonis Mat m. , short-leaved m. Musineon (UMBELL) 162 divaricatum Leafy musineon Myosotis (BORAGI) 175 sylvatica Wood forget-me-not 244 Myosurus (RANUNC) mouse-tail 115 aristatus Sedge m . , bristly m . minimus Least m . , tiny m ., common m . Myriophyllum (HALORA) 11 spicatum Spiked water-milfoil Nemophilia (HYDROP) 174 breviflora Great Basin nemophila Nepeta (LABIAT) 179 cataria Catnip, catmint Nuphar (NYMPHA) 11 polysepalum Spatter-dock, Indian pond lily Oenothera (ONOGRA) primrose 159 breviflora Short-flowered evening p . caespitosa Rock-rose evening p . , butte p . flava Long-tubed evening p . nuttallii White evening p. , Nuttall's p. strigosa Long-leaf evening p. Opuntia (CACTAC) 157 fragilis Brittle cholla polyacantha Starvation cholla, Plains prickly pear Orobanche (ORBAN) 187 fasciculata Clustered broomrape multiflora Orthocarpus (SCROPH) 180 luteus Yellow owl-clover Oryzopsis (GRAMIN) ricegrass 73 asperifolia Rough-leafed r. exigua Little r . hymenoides Indian r. Osmorhiza (UMBELL) 165 chilensis Mountain sweet-root depauperata Blunt-fruit sweet-root Oxyria (POLYGO) 97 digyna Mountain sorrel Oxytropsis (LEGUMI) crazyweed 151 campestris Slender c . , field c . deflexa Pendent-pod c . lagopus Rabbit-foot c . sericea Silky c . viscida Sticky c . Paeonia (PAEONI) 23 brownii Brown's peony 245 Panicum (GRAMIN) witchgrass 73 capillare Common w. , old-w . occidentale Western w. Parietaria (URTICA) 96 pennsylvanica Pellitory Parnassia (SAXIFR) grass-of-parnassus 134' fimbriata Fringed g., Rocky Mt. g. palustris Wideworldg. parviflora Small-flowered g . Pastinaca (UMBELL) parsnip 161 sativa Common p . , wild p . Pedicularis (SCROPH) louseowrt 185 bracteosa Bracted 1 . contorta White coiled-beak 1. cystopteridifolia Fern-leaved 1. groenlandica Pink elephants, elephants' s head parryi Parry's 1. racemosa Leafy 1., sickletopl. Penstemon (SCROPH) penstemon 185 arenicola attenuatus Sulfur p. , taper-leaved p. cyaneus Dark-blue p . deustus Hot-rock p. eriantherus Crested tongue p. , fuzzytongue p. fruticosus Shrubby or bush p. montanus Montain beardtongue procerus ' Tiny-bloom p. , small-flowered p. radicosus Matroot p . rydbergii Rydberg'sp. Whippleanus Whipple's p. Perideridia (UMBELL) 162 gairdneri Gairdner's yampah Phacelia (HYDROP) phacelia 174 franklinii Franklin's p. hastata Whiteleaf p . , silver leaf p . linearis Threadleaf p . sericea Silky p . Phalaris (GRAMIN) 56, 58 arundinacea Reed canary grass Phelum (GRAMIN) timothy 74 alpinum Alpine t. , mountain t. pratense Common t. 246 Phlox (POLEMO) phlox 172 caespitosa Tufted p . , clumped p. hoodii Hood's p. longifolia Long-leaf p . multiflora Many-flowered p . pulvinata Cushion p . Phyllodoce (ERICAC) Mountain-heath 166 empetriformis Red m . , pink m . Physaria (CRUCIF) 130 australis didymocarpa Common twinpod Physocarpus (ROSACE) 137 malvaceus Mallow ninebark Picea (PINACE) spruce 39 engelmanni Engelmann, white, mtn. , or silver s . glauca White, Can., Black Hills, or skunk s . Pinus (PINACE) pine 39 albicaulis Whitebark p . contorta Lodgepole, black, scrub, or tamarack p . flexilis Limber p . Plagiobothrys (BORAGI) 176 scouleri Seoul er's popcorn-flower Plantago (PLANTA) plantain, ribwort 188 elongata Slender p. lanceolata English p . buckhornp., r. major Common p. , nippleseed p. patagonica Indian-wheat Poa (GRAMIN) bluegrass 74 alpina Alpine b. arida Dryland b. , prairie speargrass bulbosa Bulbous b. compressa Canada b. cusickii Cusick's b. fendleriana Mutton grass grayana Gray's b. interior Inland b. juncifolia Alkali b . leptocoma Bog b. nervosa Wheeler's b. nevadensis Nevada b. palustris Fowl b . , meadow-grass 247 Poa (GRAMIN) bluegrass continued patter sonii Patterson's b . pratensis Kentucky b. reflexa Nodding b. rupicola Timberland b . sandbergii Sandberg'sb. scabrella Pine b. Polemonium (POLEMO) polemonium 173 occidentale Western p . pulcherrimum Showy p . , skunk-leaved p . viscosum Skunk p., sticky p. Polygala (POLYGA) 21 alba Polygonum (POLYGO) smartweed, knotweed 98 achoreum amphibium Water s . , white ladysthumb aviculare Doorweed, prostrate k. bistortoides Am. bistort, Western b., snakeweed confertiflorum Closeflowered k . convolvulus Dullseed, cornbind, black bindweed douglasii Douglas' k. kelloggii Kellogg'sk. viviparum European bistort, alpine b. viviparous b . Polypogon (GRAMIN) polypogon 58, 61 monspeliensis Rabbitfoot p. , annual beard-grass Polystichum (POLYPO) 37 lonchitis Mountain holly-fern scopulinum Rock sword-fern Populus (SALICA) cottonwood, aspen 89 acuminata Rydberg'sc. angustifolia Black c, mt. c, narrow-leaved c. balsamifera Balsam poplar tremuloides Aspen, quaking a., trembling a. Porterella (CAMPAN) 192 carnulosa Porterella Potamogeton (POTAMO) pondweed 40 alpinus Northern or reddish p . fibrillosus Fibrous-stipuled p . filiformis Slender-leaved p . foliosus Close-leaved p . gramineus Grass-leaved p . 248 Potamogeton (POTAMO) pondweed continued natans Broad or floating-leaved p. nodosus Long-leaved p . pectinatus Fennel-leaved p . praelongus Long- or white-stalked p. richardsonii Richardson's p . robbinsii Robins' p. Potentilla (ROSACE) cinquefoil 140 anserina Common silverweed argentea Silvery c . arguta Tall, valley or glandular c. biennis Biennial c . diversifolia Diverse-leaved c . , vari-leafc. fruticosa Shrubby c . , yellow rose glandulosa Sticky c, gland c. gracilis Graceful c. hippiana Woolly c . norvegica Norwegian c . ovina Sheep c . palustris Purple c. , marsh c. Prunella (LABIAT) 179 vulgaris Self-heal, all-heal Prunus (ROSACE) 137 virginiana Common chokecherry Pseudotsuga (PINACE) 38 menziesii Dougias-fir Pteridium (POLYPO) 36 aquilinum Bracken, brake-fern Pterospora (ERICAC) 165 andromedea Woodland pinedrops Puccinellia (GRAMIN) alkaligrass 79 distans Weeping a . nuttalliana Nuttall'sa. pauciflora Weak a. Purshia (ROSACE) 137 tridentata Antelope-brush, bitter-brush Pyrola (ERICAC) pyrola, winter green 166 asarifolia Alpine p . , common pink w . clorantha Green w. , greenish w. dentata Toothleaf p . minor Lesser w . , snowline p . picta White vein p . secunda One-sided w. , sidebells p. uniflora Woodnymph, single delight, wax-flower 249 Ranunculus (RANUNC) buttercup 115 abortivus Small-flowered b. alismaefolius Plamtamleaved b. aquatilis White water-b. , water crowfoot cymbalaria Shore or seaside b. eschscholtzii Subalpine b. flammula Creeping b., lesser spearwort glaberrimus Sagebrush b . gmelinii Small yellow water- b . inamoenus Unlovely b . jo vis Jove s b. macounii Macoun's b . natans Floating water-b. occidentalis Western b . orthorhynchus Straightbeak b. sceleratus Celeryleaved crowfoot or b . unicinatus Little b . Ratibida (COMPOS) columnifera Prairie coneflower Rhamnus (RHAMNA) alnifolia Rhus (ANACAR) radicans trilobata Alder buckthorn Posion ivy, poison oak Smooth sumac, squawbush, skunkbush Ribes (GROSSU) current, gooseberry 194 154 154 136 Squaw c . , wax c . Stinking c . , northern black c Whitestem g . Swamp g . , swamp black g . Alpine prickly c. , mt. g. Missouri g. Sticky c . cereum hudsonianum inerme lacustre montigenum setosum viscosissimum Rorippa (CRUCIF) yellowcress curvisiliqua Western y. islandica Marsh y. , hispid y. nasturitium-aquaticum Water-cress obtusa Rosa (ROSACE) acicularis woodsii Rubus (ROSACE) idaeus parviflorus Bluntleaved y . Prickly rose Wood's rose Red raspberry Thimbleberry 130 142 142 250 Rudbeckia (COMPOS) 200 occidentalis Black-head, W. coneflower Rumex (POLYGO) dock, sorrel 100 acetosella crispus maritimus occidentalis paucifolius salicifolius venosus Sagina (CARYOP) saginoides Alpine or arctic pearlwort Sagittaria (ALISMA) cuneata Arumleaf arrowhead, wapato Salix (SALICA) willow Sheep, red, cow, mt. or horse s. Curly, sour or yellow d. Seaside d. , golden d. Western d . Alpine or mt . s . Willow d. , narrow-leaved d. Veiny d. , winged d. , wild begonia 107 90 arctica bebbiana brachycarpa commutata dodgeana drummondiana farriae fluviatilis geyeriana glauca lasiandra monticola myrtillifolia nivalis phylicifolia riticulata rigida rotundifolia scoul eriana Arctic w . Bebb w . Short-fruited w . Undergreen w. , variable w Dodge w . Drummond w . Farr 's w . River w . Geyer w . Glaucous w . Pacific w. , red w. Mountain w . Blueberry w. bilberry w. Snow w . Tea-leaved w . Net veined w . Yellow w . Roundleafed w . Scouler w . Wolf's w. Russian thistle, tumbleweed wolfii Salsola (CHENOP) kali Sambucus (CAPRIF) racemosa Elderberry Sanicula (UMBELL) graveolens Sierra' sanicle Saponaria (CARYOP) officinalis Bouncing bett, soapwort 101 190 161 107 251 Sarcobatus (CHENOP) 101 vermiculatus Black greasewood Saxifraga (SAXIFR) saxifrage 134 arguta Brook s . bronchialis Matted s. , spotted s. caespitosa Tufted s . cernua Nodding s. occidentalis Western s. , redwool s. oregana Bog s. , Oregon s. rhomboidea Diamondleaf s . Schedonnardus (GRAMIN) 60 paniculatus Tumblegrass Scirpus (CYPERA) bulrush 54 acutus Hardstem b. , viscid b. americanus American b. , three-square b. microcarpus Small-fruit b . olneyi Olney'sb. Scolochloa (GRAMIN) 62 festucacea Fescue scolochloa Scutellaria (LABIAT) skullcap 178 galericulata Marsh s. , willow-weed s. Sedum (CRASSU) 131 lanceolatum Lanceleaved stonecrop rhodanthum Rose crown roseum King's crown Selaginella (SELAGI) 1 densa Compact selaginella Senecio (COMPOS) groundsel, butterweed 219 canus Woolly g . crassulus Thick-leaved g . cymbalarioides Few-leaved g., alpine meadow b. dimorphophyllus Payson'sg. fremontii Dwarf mountain b . hydrophilis Alkali-marsh b. integerrimus Western g. , one-stemmed b. lugens Black-tipped b . pauperculus Balsam g., Canada b . pseudaureus Streambankb. serra Butterweed g. , tall b. sphaerocephalus Mountain marsh b . strepthanthifolius Rocky Mt. b. , cleft-leaf g. triangularis Arrowleaf g . Setaria (GRAMIN) 57 viridis Green bristlegrass 252 Shepherdia (ELEAGN) 157 canadensis Canada buffalo -berry, russet b., soapberry Sibbaldia (ROSACE) 138 procumbens Creeping sibbaldia Silene (CARYOP) silene 109 acaulis Moss campion, moss pink, cushion pink antirrhina Sleepy catchfly menziesii Menzies' s. noctiflora Nightflower s . , sticky cockle oregana Oregon s . parryi Parry's s. Sisymbrium (CRUCIF) tumblemustard 130 altissimum Jim Hill mustard, t. loeselii Loesel t. Sisyrinchium (IRIDAC) 85 angustifolium Blue-eyed grass, blue star, eye-bright Sitanion (GRAMIN) 58 hystrix Bottlebrush squirrel tail Sium (UMBELL) 161 suave Hemlock water-parsnip Smelowskia (CRUCIF) smelowskia 123 calycina Alpine s. , Siberian s. Smilacina (LILIAC) solomon-plume 85 racemosa False spikenard, western s. stellata Starry s . , star-flowered s . Solanum (SOLANA) nightshade 180 sarrachoides Hairy n. triflorum Cut-leaved n. Solidago (COMPOS) goldenrod 221 canadensis Canada g., meadow g. gigantea Smooth g. , late g. missouriensis Missouri g. multiradiata Northern g . nana Low g . nemoralis Gray g. , field g. Sonchus (COMPOS) 201 asper Prickly sow-thistle Sorbus (ROSACE) 137 scopulina Cascade mountain-ash Sparganium (SPARGA) bur-weed 81 angustifolium Narrowleaf or floating b . 253 Sparganium (SPARGA) continued emersum Simplestem b . minimum Small b . Spartina (GRAMIN) 57 gracilis Alkali cordgrass Spergularia (CARYOP) sandspurry 109 marina Saltmarshs. rubra Red s . Sphaeralcea (MALVAC) 154 coccinea Red globe-mallow Spiranthes (ORCHID) 86 romanzoffiana Ladies-tresses, pearl-twist Spirea (ROSACE) spirea 143 betuifolia Shiny-leafs. densiflora Subalpines. Sporobolus (GRAMIN) 58 cryptandrus Sand dropseed Spraguea (PORTUL) 105 umbellata Pussypaws Stellaria (CARYOP) starwort 109 calycantha Northerns. crassfolia Thickleaved s . cripa Criped s . longifolia Longleaved s . longipes Longstalks. obtusa Bluntsepaled s . umbellata Umbellate s. Stephanomeria (COMPOS) skeletonweed 222 runcinata Runcinate-leaved s . tenuifolia Narrow-leaved s. Stipa (GRAMIN) needlegrass 80 comata Neddle-and thread occidentalis Western n. richardsonii Richardson's n. viridula Green n Strep topus (LILIAC) 83 amplexifolius Clasping-leaved twisted-stalk Suaeda (CHENOP) 102 depressa Pahute weed Subularia (CRUCIF) 120 aquatica Awlwort Swertia (GENTIA) 169 perennis Swertia 254 Symphoricarpos (CAPRIF) snowberry 191 albus Common s . occidentalis Wolfberry, western s. oreophilus Mountain s . Tanacetum (COMPOS) 201 vulgare Common tansy Taraxacum (COMPOS) dandelion 222 ceratophorum Horned d. laevigatum Red-seeded d. officinale Common d . Telesonix (SAXIFR) 132 jamesii James' saxifrage Tetradymia (COMPOS) horse-brush 198 canescens Gray h. , spineless h. Thalictrum (RANUNC) meadowrue 118 occidentale Western m. sparsiflorum Fewflowered m . venulosum Veiny m. Thelypodium (CRUCIF) thelypody 131 integrifolium Entireleaved t. sagittatum Slender t. Thermopsis (LEGUMI) 143 montana Mountain thermopsis Thlaspi (CRUCIF) 131 arvense Field pennycress, fanweed parviflorum Smallflowered pennycress Tofieldia (LILIAC) 83 glutinosa Sticky tofieldia Townsendia (COMPOS) townsendia 223 exscapa Easter daisy leptotes Common t. montana Mountain t. parryi Parry's t. Tragopogon (COMPOS) salsify 223 dubius Yellow s. porrifolius Vegetable oyster, s. pratensis Meadows., Jack-go-to-bed-at-noon Trifolium (LEGUMI) clover 152 haydenii Hayden's c. hybridum Alsike c . longipes Long-stalked c . parryi Parry's c . pratense Red c . repens White c . , Dutch c . 255 Triglochin (JUNCAG) arrowgrass 40 concinnum Graceful a. maritimum Seaside a. palustre Marsh a. Trisetum (GRAMIN) trisetum 80 spicatum Spike t., downy oat-grass wolfii Wolf's t., beardless t. Trollius (RANUNC) 112 laxus Globeflower Typha (TYPHAC) cat-tail 81 angustifolia Lesser c. latifolia Common c . Urtica (URTICA) 96 dioica Stinging nettle Uticularia (LENTIB) bladderwort 188 minor Lesser b . vulgaris Common b. Vaccaria (CARYOP) 107 segetalis Cowcockle, cowherb Vaccinium (ERICAC) huckleberry 167 caespitosum Dwarf bilberry, dwarf h. globulare Globe h. myrtillus Dwarf bilberry , low bilberry occidentale Western h. , w. bog blueberry scoparium Grouseberry, whortleberry Valeriana (VALERI) valerian 192 dioica Northern v. edulis Edible v. , tobacco-root occidentalis Western v. Verbascum (SCROPH) 181 thapsus Common mullein, flannel m. Verbena (VERBEN) 19 bracteata Bracted verbena Veronica (SCROPH) speedwell 187 americana American brooklime peregrina Purslane s. scutellata Marsh s. , skullcap s. serpyllifolia Thyme-leaved s . wormskjoldii American alpine s. Vicia (LEGUMI) 144 americana American vetch Viguiera (COMPOS) 194 multiflora Viguiera 256 Viola (VIOLAC) violet adunca Early blue v. , hook v. canadensis Canada v. macloskeyi Small white v. nephrophylla Northern bog v. nuttallii Nuttall's v. pahistris Marsh v. purpurea Goosefoot v. , purplish v. Woodsia (POLYPO) orogana Woodsia scopulina Rocky Mt. woodsia Wyethia (COMPOS) wyethia amplexicaulis Northern w . , Mule's-ears helianthoides White-rayed w . , white-head Xerophyllum (LILIAC) tenax Indian basket-grass , beargrass Zannichellia (ZANNIC) palustris Horned pondweed Zigadenus (LILIAC) elegans Glaucous zigadenus venenosus Meadow death-camas 257