Monographs Details: Astragalus tener A.Gray
Authors:Rupert C. Barneby
Authority: Barneby, Rupert C. 1964. Atlas of North American Astragalus. Mem. New York Bot. Gard. 13(2): 597-1188.
Family:Fabaceae
Scientific Name:Astragalus tener A.Gray
Discussion:

327.  Astragalus tener

Variable in stature, thinly strigulose with fine, straight, appressed and narrowly ascending hairs up to 0.3-0.6 mm. long, the herbage sometimes subglabrous, deep green, the leaflets always glabrous above, the inflorescence (and often the peduncles and rachis of the upper leaves) black-strigulose or -villosulous; stems solitary and erect, or 3 (the 2 lateral ones ascending from the axils of oblanceolate cotyledons 1-1.5 cm. long), or diffusely branching from 1-several nodes and the lateral branches all diffuse and incurved-ascending, the principal ones (4) 6-30 cm. long; stipules membranous or membranous-margined, pallid, broadly ovate, ovate-acuminate, or the usually narrower and longer upper ones broadly lanceolate, about semiamplexicaul, glabrous dorsally, black- or sometimes white-ciliate; leaves (2) 3-9 cm. long, all petiolate but the upper ones shortly so, with 7-17 flat or loosely folded, rather distant leaflets 3-16 mm. long, varying in outline from broadly obovate-cuneate or obcordate to lanceolate or narrowly oblong and then either retuse, truncate, or obtuse, or linear-elliptic and acute, the leaflets of a given plant either homomorphic (and of either a broad or narrow type), or dimorphic (when of narrow type in the upper leaves); peduncles erect, incurved-ascending, or sometimes divaricate in fruit, 2.5—7 cm. long, either a little longer or shorter than the leaf; racemes subcapitately 3-12-flowered, the flowers loosely spreading, the axis scarcely elongating, 2-8 mm. long in fruit; bracts membranous, ovate or lanceolate, 0.7—2 mm. long; pedicels at anthesis slender, ascending, 0.5-1 mm. long, in fruit a trifle thickened, arched outward, 1-2.3 mm. long; bracteoles 0 (rarely a minute scale); calyx 2.7—5.4 mm. long, densely strigulose-villosulous with black and sometimes a few intermingled white hairs, the disc subsymmetric, the teeth broadly subulate, the ventral pair sometimes broader or longer than the rest, the whole becoming papery, ruptured, marcescent; petals pink-purple, drying violet, the inner margin of the wing-tips pale or white, the banner with a large, pale, striate eye in the fold of the limb, perhaps sometimes subuniformly pale purple or lilac; banner recurved through 35—40°, ovate-cuneate or broadly lance-cuneate, deeply notched, 5.2-11.8 mm. long; wings shorter, the blades oblanceolate or obliquely elliptic, obtuse or erose- emarginate, gently incurved; keel 3.4-6.4 mm. long, the blades broadly half- obovate or nearly half-circular, incurved through 95-120° to the bluntly deltoid, sometimes obscurely porrect apex; anthers 0.2—0.5 mm. long; pod ascending, horizontal, or declined, sessile, linear- or narrowly lance-oblong in profile, straight, a trifle decurved, or lunately incurved, (6) 7-16 (20) mm. long, 1.7-3.5 mm. in diameter, rounded at base, shortly acuminate at apex, bluntly and sometimes only obscurely triquetrous, keeled ventrally by the suture, rounded laterally, openly sulcate dorsally, the thinly fleshy, green, glabrous, strigulose, or rarely villosulous valves becoming stiffly papery and brownish, finely reticulate, inflexed as a complete or subcomplete septum 0.6-1.2 mm. wide; ovules 5-14; seeds (poorly known) apparently brown and smooth, about 1.3-1.5 mm. long.

Narratives:Astragalus tener