Astragalus longissimus (M. E. Jones) Barneby

Atelophragma townsendii Rydb. Bull. Torrey Club 55: 163. 1928.
A perennial; stems 3-5 dm. high, angled; strigose, somewhat flexuose; leaves 5-8 cm. long; stipules deltoid, 4-5 mm. long; leaflets 15-27, oblong or elliptic to nearly linear, long-pilose on both sides, glabrate in age above, 5-12 mm. long, 1.5-4 mm. wide; peduncles about 1 dm. long, strict; racemes elongate, dense, 5-15 cm. long; bracts subulate, 2-4 mm. long; calyx densely black-hairy, the tube 3 mm. long, the teeth subulate, 1.5 mm. long; corolla cream-colored, about 7 mm. long; banner obovate, strongly arched; wings about as long, the blade broadly lunate; pod black-strigose, the stipe 4—5 mm. long, the body oblong, tapering at each end, about 2 cm. long, 5 mm. wide, deeply sulcate on the lower suture, the septum fully 1 mm. broad; seeds about 16.
Type locality: Sierra Madre, Chihuahua. Distribution: Chihuahua.

Atelophragma longissimum (M. E. Jones) Rydb. Bull Torrey Club 55: 162. 192S.
Astragalus Rusbyi longissimus M. E. Jones, Proc. Calif. Acad. II. 5: 662. 1895.
A cespitose perennial, with a woody root ; stems several, about 3 dm. high, branched, angled, sparingly strigose; leaves ascending, about 1 cm. long, the rachis sulcate, sparingly hairy; stipules lanceolate, 2-3 mm. long; leaflets 25-37, oblong-oblanceolate, 8-20 mm. long, 3-4 mm. wide, light-green, glabrous above, sparingly strigose beneath, retuse or rounded at the apex ; peduncles 1-2 dm. long; racemes lax, about 1 dm. long; bracts lance-subulate, 2 mm. long; pedicels 2 mm. long; calyx strigose often with black hairs, the tube 2 mm. long, the teeth subulate, 1 mm. long; corolla straw-colored, 3-4 mm. long; banner obovate, strongly arched at the middle, even slightly reflexed; wings about as long, the blade oblanceolate, falcate; keel-petals shorter, the blade obliquely obovate, rounded at the apex; pod white-strigose, the stipe 5-6 mm. long, the body lance-oblong, acute at each end, 1 5—1 S mm. long, 4 mm. wide, sulcate on the lower suture, the septum 1.5 mm. wide; seeds 12-16.
Type locality: Chihuahua. Distribution: Chihuahua.

Astragalus longissimus adalah spesies tumbuhan yang tergolong ke dalam famili Fabaceae. Spesies ini juga merupakan bagian dari ordo Fabales. Spesies Astragalus longissimus sendiri merupakan bagian dari genus Astragalus. Nama ilmiah dari spesies ini pertama kali diterbitkan oleh (M.E.Jones) Barneby.

Astragalus longissimus là một loài thực vật có hoa trong họ Đậu. Loài này được (M.E.Jones) Barneby miêu tả khoa học đầu tiên.