Astragalus Geyeri var. Geyeri

Title

Astragalus Geyeri var. Geyeri

Authors

Rupert C. Barneby

Scientific Name

Astragalus geyeri A.Gray var. geyeri

Description

283a. Astragalus Geyeri var. Geyeri

Annual or occasionally perennant; leaflets (3) 7-13, linear-oblong, narrowly oblanceolate, or linear-elliptic, rarely (in some lower leaves) obcordate, 3-17 mm. long, the terminal one nearly always longer than the last pair; pod rounded dorsally; ovules 10-18.—Collections: 63 (xiv); representative: C. P. Smith 3654 (DS); J. & C. Christ 16,695, 18,546 (NY, RSA); Ripley & Barneby 6514 (CAS, IDS, RSA); Palmer 294 in 1893 (WIS); C. L. Hitchcock 15,755 (NY, RSA, WS); Peck 21,827, 25,759 (CAS, RSA, WILLU); E. Nelson 4911 (NY); Eastwood & Howell 9469 (CAS, WS); Holmgren 1067 (UTC, WS); Jones 1781 (CAS, NY, POM); Holmgren & Hansen 3289 (NY, WS).

Sandy flats and valley floors, depressions in mobile or stablized dunes, and along draws in gullied bluffs or knolls, mostly 2500-5500 feet, to the south with Larrea, northward with sagebrush, widely dispersed over the Great Basin and common locally, from westcentral Nevada and adjoining California to southeastern Oregon, the Snake River plains in southern Idaho, and the Colorado Basin in east- central Utah, extending more rarely northeast and up to 7000 feet to the upper forks of the North Platte and Wind Rivers in Wyoming; apparently isolated at about 400 feet at the Great Bend of the Columbia River in southeastern Washington (Walla Walla County).—Map No. 122.—Late April to July (August).

Astragalus Geyeri (Charles Andreas Geyer, 1808-1853, Austrian plant collector, crossed the continent in 1843—4) Gray in Proc. Amer. Acad. 6: 214. 1864, based on Phaca annua (annual) Geyer in Lond. Jour. Bot. 6: 213. 1847.—"...in the drift-sand plains of the Upper Platte River... (n. 1)."—Holotypus, K! isotypi, BM, G, GH, OXF, P!—Non A. annuus DC., 1802.

The typical form of the Geyer milk-vetch is a lowly and inconspicuous plant, although pretty enough at close quarters, when the beauty of the greatly oblique, bladdery fruits of papery-membranous texture and the symmetry of the tiny, whitish or (in northcentral Nevada) rarely purple flowers can be appreciated. Other notable features of var. Geyeri are its few leaflets of narrow outline, of which the terminal one is usually much the longest, and the production of the first fruiting racemes close to the ground on what appear, to the casual glance, subradical scapes. The species is not very variable. In Nevada, Utah, Oregon, and Idaho it is found in the hottest and most arid valleys where its life span is ordinarily a matter of three or four months. A shower at the critical moment may prolong its active days until the base of the stems and the taproot become a little indurated or woody; even so it is in this area a true monocarpic annual. In the cooler climate around the foothills of the Sweetwater Mountains in Wyoming, where A. Geyeri reaches an altitude of 7000 feet, the plants tend to persist into a second season. In Sweetwater County, Ripley and I found one colony in which every individual plant had come through the preceding winter and none had germinated as yet from last year’s seed. More commonly, however, diminutive annual and first-year plants are found in flower and fruit simultaneously, together with the low, tufted, basally indurated biennial phase. While there seems to be something individual about these Wyoming populations, they do not differ in the form of their essential parts.

The Geyer milk-vetch is known for certain in California only from one spot in eastern Mono County, just across the Nevada line. It is to be expected, and has perhaps been found, in the Basin sector of Lassen or Sierra County. A specimen labeled "California" (Lemmon 66 in 1875, NY) may have come from the northeast corner of the State, but the record needs authenticating.

The first collection of A. Geyeri dates back to Douglas’s exploration of the Columbia Basin. His specimens are dated 1830 (BM) and 1835 (K), but the only locality recorded was "Oregon."