Astragalus oophorus var. lonchocalyx

Similar to var. oophorus, but differing in the relatively long and narrow flower, as described in the key; calyx-tube glabrous, the teeth 2.5-4 mm. long; banner oblanceolate, 20.5-24 mm. long, 7-10.5 mm. wide; wing-blades linear-oblong, truncate or subemarginate, 8.7-11.5 mm. long, 2-2.7 mm. wide; keel-blades 6.9-7.9 mm. long, 2.6-3.4 mm. wide; ovules 34-38.—Collections: 4 (iii); representative: Ripley & Barneby 3232, 3486 (RSA); B. F. Harrison 12,241 (NY).

Dry gravelly hillsides and stony flats, associated with and sometimes sheltering under sagebrush, on limestone, 6000-6600 feet, apparently local, known only from the low mountain ranges about the headwaters of the Muddy River, Lincoln County, Nevada, and adjoining Iron County, Utah.—Map No. 105.—May to June.

Astragalus oophorus var. lonchocalyx (with long calyx) Barneby in Leafl. West. Bot. 7: 194. 1954.—"Fay, 3 miles east of Deer Lodge, Lincoln Co., April 24, 1939, Percy Train 2630"—Holotypus, NA! isotypi, NY, TEX!

The var. lonchocalyx might be described in loose terms as combining the growth-habit of var. oophorus with the long, narrow flower of A. megacarpus. In other respects, there is no suggestion of transition between the two species; var. lonchocalyx is no doubt derived directly from A. oophorus through an independent mutation.