Monographs Details: Astragalus purshii var. concinnus Barneby
Authors:Rupert C. Barneby
Authority: Barneby, Rupert C. 1964. Atlas of North American Astragalus. Mem. New York Bot. Gard. 13(2): 597-1188.
Description:Variety Description - Dwarf, tufted, acaulescent or nearly so, the herbage densely pannose (as in A. utahensis); leaves 1.5-7 cm. long, with (5) 7-9 (11) obovate, obovate-cuneate, or broadly oval, more rarely some broadly elliptic, obtuse or truncate leaflets 3-12 (15) mm. long; racemes (2) 3-8-flowered; calyx 9-13 (14) mm. long, the deeply campanulate to broadly cylindric, commonly tumid tube 7.8-10.8 mm. long, (3.6) 4-5.5 mm. in diameter, the teeth 1.8-3 (4) mm. long; petals pink- purple; banner rhombic- or flabellate-obovate, on the average broader than that of var. tinctus or var. glareosus, (19) 20-24 mm. long, (11.4) 12-15 mm. wide; wings 18-20.5 mm. long, the claws 9.8-10.9 mm., the blades 9.7-11.8 mm. long, 2.8-3.4 mm. wide; keel 15.6-17.6 mm. long, the claws 9.9-10.9 mm., the blades (6) 6.9-7.6 mm. long, 2.8-3.6 mm. wide; pod as in var. Purshii; ovules 28-38.

Distribution and Ecology - Gravelly hillsides and valley flats, nearly always among sagebrush, commonly on limestone, mostly 4300-7000 feet but ascending on Mt. Borah up to 9000 feet, locally plentiful on and near the Lost-Salmon River divide in eastcentral Idaho, extending east across the Bitterroots to the Beaverhead and upper Jefferson Rivers in southwestern Montana.—Map No. 87.—May to July.

Discussion:The broad, blunt, softly white-tomentose leaflets of var. concinnus, the somewhat baggy, purplish calyx and the ample banner all suggest a condensed phase of A. utahensis; but the fewer (mostly 5-9) leaflets readily distinguish flowering plants, and the pod is that of A. Purshii, of which it is the only purple-flowered representative in its compact area of dispersal. The var. glareosus approaches the range of var. concinnus in the Sawtooth foothills and in the neighborhood of the sink of Big Lost River, but differs in its more numerous, narrow, commonly subacute leaflets and by its ventrally furrowed pod. On account of its dwarf stature, white foliage, and proportionately large and generously proportioned flower, var. concinnus is one of the most decorative of the Argophylli.
Distribution:Idaho United States of America North America| Montana United States of America North America|