Monographs Details: Astragalus whitneyi var. confusus Barneby
Authors:Rupert C. Barneby
Authority: Barneby, Rupert C. 1964. Atlas of North American Astragalus. Mem. New York Bot. Gard. 13(1): 1-596.
Family:Fabaceae
Description:Variety Description - Relatively robust but sometimes low, the decumbent, ascending, or erect stems 1-3 (sometimes in flower when only 0.5) dm. long, the herbage gray- or silvery-villosulous with shorter, curly or sinuous, and longer, straight or incurved- ascending hairs up to 0.45—0.8 mm. long; leaves (2) 3—10 cm. long, with (7) 13-21 elliptic or oblanceolate, or (in some lower leaves) obovate, obtuse, acute, or emarginate leaflets (3) 5—20 mm. long; racemes (5) 8—16-flowered, the axis (1) 1.5—4 cm. long in fruit; calyx (5.8) 6.1-9.3 mm. long, the tube (4) 4.6-5.9 mm. long, (3) 3.4—4.6 mm. in diameter, the teeth (1.5) 1.8—3.6 mm. long; petals whitish tinged with pale pink or lavender, sometimes drying ochroleucous; banner (12.8) 13.5-17.2 mm. long, 7.2-10.2 mm. wide; wings (12.1) 12.6-15.4 mm. long, the claws (5) 5.4—6.5 mm., the blades (7.3) 8—10 mm. long, 2.8-4 mm. wide; keel (11.2) 11.8-13.8 mm. long, the claws 5-6.4 mm., the blades (6.3) 6.8-8.1 mm. long, (2.8) 3-3.8 mm. wide; stipe of the pod 4-9 mm. long, the body (1.7) 2—6 cm. long, (1) 1.3—2.5 (when pressed up to 2.8) cm. in diameter, the valves strigulose; ovules 22—30 (37).

Distribution and Ecology - Open slopes and hillsides, in sandy or gravelly, basaltic or sometimes granitic soils, usually associated with and often sheltering under sagebrush, 4400—8000 (8900) feet, locally plentiful in the lake country of northeastern California and adjoining Oregon, east (perhaps interruptedly) to the Owyhee-Humboldt divide in northeastern Nevada and southeastern Idaho; somewhat disjunctly on the south slope and crest of the Sawtooth Mountains in southcentral Idaho. Map No.32. April to July.

Discussion:The var. confusus can be visualized as a coarser, large-flowered version of the preceding, on the average more densely and loosely pubescent. It occupies a more southern range, mostly at lower elevations, characteristically associated with sagebrus. It is especially common in Modoc County, California, and adjoining Lake County, Oregon, and again in Owyhee County, Idaho; but I have no intervening record from Harney or Malheur Counties. The variety reappears on the north rim of the Snake River Plains in a narrow strip of foothill country extending from the Craters of the Moon to Sun Valley, where it reaches almost up to the 9000-foot contour near Galena Summit. In this area the pod is sometimes nearly glabrous, but the ovary is always hairy. In northeast California, along Pit River and near Susanville in southwestern Modoc and Lassen Counties, there occurs a balloon milk-vetch which combines the vigorous stature and large, pinkish flowers of var. confusus with the thinner vesture and open raceme often associated in var. siskiyouensis. These populations, in some of which the pod varies from glabrous to puberulent from one plant to the next (Ripley & Barneby 5747, CAS, NY, RSA), have been referred to var. confusus on the basis of their ecology and distribution, but they are morphologically intergradient to var. siskiyouensis.
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|