Astragalus lentiginosus var. platyphyllidius (Rydb.) M.Peck
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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
"Type collected on Pine Creek, Gilliam County, Oregon, June 7, 1891, J. B. Leiberg 171 ... " Holotypus, NY! isotypi, GH, ORE, US!
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Synonyms
Cystium platyphyllidium Rydb., Cystium merrillii Rydb., Astragalus merrillii (Rydb.) Tidestr., Cystium cornutum Rydb., Astragalus lentiginosus var. cornutus (Rydb.) M.Peck
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Description
Variety Description - Perennial, resembling var. lentiginosus in growth-habit but commonly coarser, thinly strigulose with subappressed hairs up to 0.3-0.55 mm. long, the stems and herbage subglabrous, the thick-textured, green or subglaucescent leaflets glabrous above, sometimes ciliate, the inflorescence commonly black-strigulose; stems (0.7) 1—3 (3.5) dm. long, stramineous or pallid, floriferous from near or below the middle; leaves (4) 5—11 cm. long, with (7) 11—17 (19) broadly obovate-cuneate, elliptic, or suborbicular, obtuse, retuse, truncate and apiculate, or rarely rhombic- elliptic and acute leaflets (4) 7—20 mm. long; peduncles 1—5 cm. long; racemes shortly but loosely (5) 7-15-flowered, the axis little elongating, 1-3.5 cm. long in fruit; calyx (8) 8.5—12.5 mm. long, the cylindric or deeply campanulate tube (5) 5.5-8 (9) mm. long, 2.3-4 (4.4) mm. in diameter, the teeth 2.4-5 mm. long; petals whitish, the keel- and sometimes the wing-tips tinged with pink or lilac; banner broadly rhombic-oblanceolate or -elliptic, (12.6) 14-21.4 mm. long, (6.1) 6.6-11.5 mm. wide; wings (11.6) 12.6-17.3 mm., the blades 6.7-10.4 mm. long; keel (shorter, or exceptionally a trifle longer than the wings) 11—15 mm. long, the blades (5.1) 5.7-7.4 mm. long, (2.2) 2.4-3.5 mm. wide; pod very variable in length, outline, and curvature, (1.3) 1.5-4 (4.8) cm. long, 7-14 mm. in diameter, the body strongly or little inflated, plumply ovoid or narrowly lance-ellipsoid, rounded or cuneately tapering at base, contracted or acuminately tapering distally into a deltoid or lance-acuminate, unilocular beak 5—15 mm. long, the whole nearly straight or lunately to hamately incurved through up to ¾-circle, openly sulcate along either or both sutures, the more or less fleshy, pale green or purple-speckled (exceptionally mottled), glabrous or less often minutely strigulose valves becoming leathery or stiffly papery, stramineous or brownish, the complete or nearly complete septum 2.2—5 (7) mm., the funicular flange (0.5)0.7-1.3 mm. wide; ovules (21) 24-32 (38).
Distribution and Ecology - Arid plains, hillsides, and valley floors, commonly on basalt and associated with sagebrush, sometimes in alkaline alluvia or sand derived from shale or sandstone, 2250-6000, and at its eastern limit up to 6700 feet, widespread and locally plentiful over most of transmontane Oregon, from John Day Valley southward into northeastern California, extreme northern Nevada, and east in scattered stations around the edge of the Snake River Plains in southern Idaho to the Bear River and upper Green River Basin in southwestern Wyoming, the Weber River in adjoining Utah, and the Yampa Valley in extreme northwestern Colorado.- Map No. 129 [Map No. 130].-May to July.
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Discussion
The var. platyphyllidius might be visualized as a coarsened version of var. lentiginosus or var. salinus, differing in its longer (commonly much longer) calyx and petals and its often larger, always thicker-walled fruits which dry out to a leathery or stiffly papery texture. It stands in a morphological gap between the group, described up to this point, of varieties with small, mostly whitish flowers and the next following group of varieties which are similar in flower-size but differ in their purple petals and more southern range. The variety is polymorphic, as described and illustrated in more detail elsewhere (Barneby, 1945, p. 104-6), and in parts of its range there are suggestions of racial differentiation although no real discontinuities in variation. The longest flowers and longest, least-swollen pods are found, both together and separately, along the north slope of the Blue Mountain system draining to the Columbia. The typi of Cystium platyphyllidium and C. cornutum were both from this region and represent respectively the glabrous-fruiting and rarer puberulent-fruiting phases which are known to occur occasionally in the same population. South of the Blue Mountains in Oregon and states adjoining to the south and east, var. platyphyllidius is usually a little smaller-flowered and its pod, which is also a little shorter, varies from little to greatly inflated. In all this region the variety is confined to volcanic soils and is sympatric with var. salinus, var. lentiginosus, or both, and is sometimes difficult to distinguish from the so-called "carinatus" form of the latter. I now feel satisfied that Leiberg 2110 from Malheur County, Oregon, which I hesitantly referred to var. carinatus in my revision (1945, p. 83) is best interpreted as an aberrant state of var. platyphyllidius with exserted keel-petals. No other collection quite like it has been seen. East of the region covered so far, in the drainage of the Green, Bear, and Yampa Rivers, the variety reappears on sedimentary (or rarely granitic) bedrock and bears flowers of moderate size and a pod nearly always inflated and of slightly less firm texture. Possibly this phase (= C. Merillii) should be detached from var. platyphyllidius, but I have found no practical method of separating it, for the pods of plants originating so far apart as Lassen County, California, and Moffat County, Colorado, are virtually indistinguishable.
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Objects
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Distribution
California United States of America North America| Oregon United States of America North America| Nevada United States of America North America| Idaho United States of America North America| Wyoming United States of America North America| Utah United States of America North America| Colorado United States of America North America|