Great Basin Naturalist Volume 38 Number 3 Article 1 9-30-1978 Utah flora: Fabaceae (Leguminosae) Stanley L. Welsh Brigham Young University Follow this and additional works at: https://scholarsarchive.byu.edu/gbn Recommended Citation Welsh, Stanley L. (1978) "Utah flora: Fabaceae (Leguminosae)," Great Basin Naturalist: Vol. 38 : No. 3 , Article 1. Available at: https://scholarsarchive.byu.edu/gbn/vol38/iss3/1 This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. The Great Basin Naturalist Published at Provo, Utah, by Brigham Young University ISSN 0017-3614 Volume 38 September 30, 1978 No. 3 UTAH FLORA: FABACEAE (LEGUMINOSAE) Stanley L. Welsh' Abstract.— A revision of the legume family, Fabaceae (Leguminosae), is presented for the state of Utah. In- cluded are 244 species and 60 varieties of indigenous and introduced plants. A key to genera and species is pro- vided, along with detailed descriptions, distributional data, and pertinent comments. Proposed new taxa are As- tragalus lentiginosus Dougl. ex Hook, var. wahweapensis Welsh; Astragalus subcinereus A. Gray var. basalticus Welsh; Hedysarum occidentale Greene var. canone Welsh; Oxytropis oreophila A. Gray var. juniperina Welsh; and Trifolium andersonii A. Gray var. friscanum Welsh. New combinations include Astragalus bisulcatus (Hook.) A. Gray var. major (M. E. Jones) Welsh; Astragalus consobrinus (Bameby) Welsh; Astragalus pubentissimus Torr & Gray var. peabodianus (M. E. Jones) Welsh; Lathyrus brachycalyx Rydb. var. zionis (C. L. Hitchc.) Welsh; Lathyrus lanzwertii Kellogg var. arizonicus (Britton) Welsh; Lathyrus langwertii Kellogg var. laetivirens (Greene) Welsh; Lupinus argenteus Pursh var. moabensis (Dunn & Harmon) Welsh; Lupinus argenteus Pursh var. ru- bricaulis (Greene) Welsh; Lupinus caudatus Kellogg var. argophyllus (A. Gray) Welsh; Lupinus caudatus Kellogg var. cutleri (Eastw.) Welsh; Lupinus pusillus Pursh var. rubens (Rydb.) Welsh; Lupinus sericeus Pursh var. barbi- ger (S. Wats.) Welsh; Lupinus sericeus Pursh var. marianus (Rydb.) Welsh; Oxytropis besseyi (Rydb.) Blankinship var. obnapiformis (C. L. Porter) Welsh; Psoralea lanceolate Pursh var. stenostachys (Rydb.) Welsh. This paper is the second in a series of likely that other large families will be rep- works leading to a definitive treatment of resented by such a large percentage of ad- the flora of Utah. The first paper dealt with ventive genera. The remainder of the the Brassicaceae (Great Basin Nat. introduced species are in genera with in- 37:279-365. 1977). The legume family, digenous species in Utah. with 304 taxa, is one of the largest present The largest genus of legumes, and prob- in the state, apparently ranked second after ably of any plant family in Utah, is Astra- the Asteraceae, but in third place following galus with 110 species and 36 varieties. the Poaceae if only the 244 specific taxa This genus has long proved troublesome to are counted. Adventive plants account for taxonomists, partly because of its great size, 45 species, or about 15 percent of the total and partly because of the complex nature of taxa in the family. This is fewer than the 18 some species. percent determined for the Brassicaceae. The definitive treatment by Dr. Rupert Weedy species represent only a small pro- C. Bameby provides a basis for under- portion of the adventive taxa; the bulk con- standing of Astragalus, and this treatment is sists of cultivated crop and ornamental dedicated to him. Generally, the specific plants. More than half of the 45 legume and infraspecific lines are rather sharply genera in Utah are known from introduced drawn, but in the Astragalus lentiginosus plants. The 24 introduced genera account complex taxa apparently grade through for only 30 species, however. It seems un- series of morphological intermediates. Some 'Department of Botany and Range Science, and Life Science Museum, Brigham Young University, Provo, Utah 84602. 225 226 Great Basin Naturalist Vol. 38, No. 3 30 taxa within Astragalus, almost a quarter lucern (Medicago sativa). Thousands of acres of the total, are endemic to Utah often on are planted to this forage crop in Utah. highly specialized soil types. The currently The writer follows the example found in proposed lists of endangered or threatened Barneby (1964, Atlas of North American As- plants are replete with Astragalus taxa. tragalus) in citing the number of specimens It is difficult to find a portion of Utah of each species examined. The numbers fol- where one or more species of Lupinus are low the discussion of each taxon, with the not present. Annual species are more com- Arabic numerals indicating the total number mon at lower elevations, but some occur at seen and the Roman numerals the number middle and even upper elevations. Specific collected by me. lines are more easily drawn among annual Fabaceae Lindley species. Perennials occur as complex groups Legume Family which tend to intergrade in endless en- Herbs, shrubs, or trees; leaves alternate, tanglements. Because of these problems, pinnately or palmately compound, or species lines have been subject to inter- simple, stipulate; flowers perfect, irregular pretation, and only the careful work of Dr. or regular, usually borne in racemes; calyx David Dunn and his students has allowed 5-lobed; petals 5 (a banner, 2 wings, and 2 meaningful interpretation of Utah lupine keels) or fewer, less commonly reduced to 1 materials. (banner), or lacking; stamens 10 or 5, or nu- Oxytropis is less complex in Utah than merous, diadelphous, monadelphous, or dis- elsewhere, primarily due to the low number tinct; pistil 1, the ovary superior, 1- or 2- of species and to the geographical isolation loculed, 1-carpelled, the style and stigma 1; of taxa known to hybridize elsewhere. Only fruit (pod) a legume or loment, sessile, sub- O. oreophila exhibits a wide spectrum of sessile, stipitate, or with a gynophore, dehis- variation in the state. cent or indehiscent. Trifolium consists of both indigenous and References introduced species which are markedly dis- tinct, both morphologically and geographi- IsELY, D. 1973. Leguminosae of the United cally. The Old World introductions listed States: I. Mimosoideae. Mem. N.Y. Bot. are among our most important forage Card. 25(1): 1-52. plants. 1975. Leguminosae of the United The legume family is economically im- States: IL Caesalpinoideae. Mem. N.Y. portant because of utilization of plants as Bot. Card. 25(2): 1-228. food for man and animals. Some representa- Welsh, S. L. 1963. Legumes of Utah L tives are poisonous and have harmed live- Preliminary report. Proc. Utah Acad. stock in the state. These are noted within 40: 200-201. the text. 1964. Legumes of Utah IL Con- Perhaps the most economically important spectus of the genera. Proc. Utah Acad. crop derived from this family is alfalfa or 41: 84-86. 1. Flowers regular, in dense heads or compact spicate racemes; stamens numer- ous (Mimosoideae) Key I Flowers irregular (only slightly so in some); stamens 10 or fewer 2 2(1). Corolla not papilionaceous, sometimes nearly regular, the upper petal en- closed by the others; stamens 10 or fewer, commonly distinct (Caesalpi- noideae) Key II - Corolla papilionaceous, the upper petal (banner) enclosing the wing and keel petals in bud, much reduced in Amorpha, or lacking in Dalea, Psorothamnus, and Parryella; stamens 10 or 5 (Papilionideae) ." 3 Sept. 1978 Welsh: Utah Flora, Fabaceae 227 3(2). Plants woody; trees, shrubs, or woody vines Key III — Plants herbaceous perennials or annuals 4 4(3). Leaves even-pinnate Key IV — Leaves odd-pinnate or simple 5 5(4). Leaflets 3 only Key V — Leaflets 5 or more, or the leaves simple Key VI Key I Flowers regular: stamens numerous (Mimosoideae) L Trees, unarmed, cultivated; flowers in umbellate heads; stamens long- exserted, the filaments commonly 20-30 mm long Albizia — Trees or shrubs, armed, indigenous; flowers in spicate racemes; stamens in- cluded or shortly exserted, the filaments less than 5 mm long 2 2(1). Spines recurved; pods flat, 10-20 mm broad, brown at maturity Acacia (greggit) — Spines straight; pods spirally coiled or if flattened then less than 10 mm broad and yellowish to tan at maturity Prosopis Key II Corolla not papilionaceous (Caesalpinoideae) 1. Plants herbaceous perennials; flowers yellow; indigenous to southeastern Utah Hoffmanseggia — Plants trees or shrubs; flowers variously colored; indigenous or introduced 2 2(1). Leaves simple, the blades rotund-ovate; flowers pink, appearing before the leaves Cersis — Leaves once or twice compound; flowers yellow, white, or greenish, appear- ing after the leaves 3 3(2). Shrubs; flowers with yellow petals, the exserted stamens to 50 mm long or more; cultivated and naturalized in Washington Co Caesalpinia — Trees; flowers with white or greenish-yellow petals, the stamens included or not much exserted; distribution broad 4 4(3). Leaves once to twice pinnate; branches often armed; flowers greenish-yellow, borne in spicate racemes; pods long and strap-shaped Gleditsia — Leaves bipinnate; branches unarmed; flower white, long-stalked, in open panicles; pods thick Gymnocladus Key III Trees, shrubs, or woody vines (Papilionideae) 1. Leaves even-pinnate, the rachis produced apically as a bristle; flowers yel- low Caragana — Leaves simple or odd-pinnate; flowers variously colored 2 2(1). Leaves simple or the lower ones 3-foliolate; plants shrubs; flowers yellow; solitary or borne in erect racemes 3 — Leaves compound; plants varying in one or more ways from above 4 228 Great Basin Naturalist Vol. 38, No. 3 3(2). Calyx split above hence 1-lipped, with 5 minute teeth; flowers borne in erect racemes; Washington Co Spartium — Calyx bilabiate, the upper lip 2-lobed, the lower 3-lobed; flowers mostly solitary axillary; Weber Co Cytissus 4(2). Plants twining woody vines; flowers large and showy, borne in terminal, pendulous racemes Wisteria — Plants trees or shrubs; flowers various, usually borne in axillary, erect or pendulous racemes 5 5(4).