Astragalus beckwithii var. weiserensis M.E.Jones
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Authors
Rupert C. Barneby
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Authority
Barneby, Rupert C. 1964. Atlas of North American Astragalus. Mem. New York Bot. Gard. 13(2): 597-1188.
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Family
Fabaceae
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Scientific Name
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Type
"Weiser, Idaho."—Holotypus, collected by Jones on April 26, 1900, POM (3 sheets); isotypus, GH!
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Synonyms
Phacomene weiserensis (M.E.Jones) Rydb., Phacomene pontina Rydb.
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Description
Variety Description - Usually stouter and coarser than var. Beckwithii; stems (1) 1.5-3.5 (7) dm. long; stipules mostly larger, (3) 4-10 mm. long; leaflets less numerous, (7) 11-17, broadly ovoid to rhombic-elliptic, (0.6) 1—2.5 cm. long; bracts 3-7.5 mm., bracteoles (0.4) 1-4 mm long; calyx glabrous except for a few hairs on the margins and inner face of the teeth, (8.5) 10.2-13.5 mm. long, the tube (4.6) 5.1-6.3 mm. long, (3) 4.3-5.2 mm. in diameter, the lance-subulate teeth (3.6) 5-7.1 mm. long; petals as in var. Beckwithii but slightly larger, the banner (16) 17-20.5 mm., the wings 17—20 mm., the keel (12.4)13—15.5 mm. long; pod similar, but often of very thick, ultimately rigid texture.
Distribution and Ecology - Gullied bluffs, river terraces, dry hillsides and sagebrush flats, in sandy, gravelly or heavy clay soils, 100-2500 feet, locally plentiful but discontinuous in range; common about the west end of the Snake River Plains in southwestern Idaho and adjoining Oregon, ascending the Snake to the Raft River and to one station in Franklin County, Idaho; apparently absent from the Grand Canyon of the Snake, but again common below the mouth of the Salmon River in the southeast corner of Washington, the north foothills of the Blue and Wallowa Mountains in Oregon, and adjoining Idaho; isolated along the lower Fraser River (Kamloops and vicinity) in southern British Columbia.—Map No. 106.—Mid- April to June.
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Discussion
As compared with var. Beckwithii, the individuality of var. weiserensis arises from the greater extreme and average dimensions of the flowers and leaflets, from the usually coarser habit of growth, and from the nearly always larger stipules, bracts, and bracteoles. Long calyx- teeth are apparently diagnostic of the variety except in a small area in Asotin County, Washington. These exceptions, which are furthermore somewhat small-flowered, have the few, large leaflets of var. weiserensis and are certainly no more than minor variants of the common large- flowered type prevalent around Lewiston and in the Wallowa foothills immediately to the north and south. The typus of the Weiser milk-vetch was derived from a population of exceptionally stout and vigorous plants found on hot, grassy hillsides above the town of Weiser. These are characterized by exceptionally broad and toughly coriaceous pods, but they cannot be distinguished usefully from the form more usual in southwestern Idaho, in which the fruit is essentially like that of typical A. Beckwithii. Rydberg stressed a broad, firm pod with broad septum as the diagnostic feature of Phacomene weiserensis, but it does not coincide with a biological reality. The disjunct populations on the Fraser River have once again flowers slightly smaller than the form common in Idaho, but are otherwise indistinguishable. I find no difference in the pod whatsoever. The Weiser milk-vetch was collected first in 1830 by David Douglas (K, in bud only).
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Objects
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Distribution
Idaho United States of America North America| Oregon United States of America North America| Washington United States of America North America| British Columbia Canada North America|