Astragalus radicans

Title

Astragalus radicans

Authors

Rupert C. Barneby

Scientific Name

Astragalus radicans Hornem.

Description

17.Astragalus radicans

Doubtless perennial, but the root-stock or caudex and the root unknown, the stems stramineous, glabrescent, the herbage green, the leaflets glabrous above, strigulose beneath with appressed or subappressed hairs up to 0.4—0.6 mm. long, the inflorescence black-hairy; stems prostrate, 1.5—8 dm. long or possibly longer, apparently elongating indefinitely during the season of growth, simple or few- branched, creeping along the ground and often rooting at the nodes; stipules 1.5-9 mm. long, those at the flowering nodes broadly obovate or suborbicular, herbaceous except for the pallid base, connate through ± half their length, much broader than the stem, glabrous or nearly so dorsally; leaves 3-32 cm. long, all petioled,  the opposite or scattered leaflets 17-31, broadly lanceolate, oblong, elliptic, or linear-lanceolate, obtuse, truncate and apiculate, or acute, flat, 3-25 mm. long; peduncles 2-26 cm. long; racemes 7—30-flowered, the flowers early declined, the axis little elongating, 1.5-5 cm. long in fruit; bracts membranous, pallid, ovate or oblong- to obovate-elliptic, obtuse or acute, (1.5) 2—4 mm. long, reflexed in age; pedicels at anthesis 0.5—1 mm. long, early arched outward, in fruit thickened, 0.7-2 mm. long, persistent; bracteoles 0; calyx 7.5-8.7 mm. long, strigulose or strigulose-hirsutulous with mostly black hairs, the subsymmetric disc 1—1.2 mm. deep, the campanulate, pallid tube 4.1—5.1 mm. long, 2.7—3.5 mm. in diameter, the lanceolate teeth 3—5 mm. long, the ventral pair broader but hardly shorter than the rest, the whole becoming papery, marcescent; petals ochroleucous or yellowish, perhaps sometimes faintly purple-tinged when fresh; banner recurved through 40—45°, broadly elliptic, oblong-oblanceolate, or ovate-cuneate, shallowly notched, (11.5) 12-14.6 mm. long, 5—7 mm. wide; wings 11-13.8 mm. long, the claws 4.4—6 mm., the narrowly oblong or elliptic, obtuse or emarginate, nearly straight blades 8—9.4 mm. long, 2—2.7 mm. wide; keel 8—10.2 mm. long, the claws 4.4-5.4 mm., the half-obovate blades 4.2—5.5 mm. long, 2.4-3 mm. wide, abruptly incurved through ±95° to the obtusely deltoid apex; anthers 0.45-0.6 mm. long; pod reflexed, subsessile or shortly stipitate, the stipe up to 1 mm. long, the body oblong or oblong-elliptic in dorsiventral view, straight or nearly so, 1.5-2.1 cm. long, 5-8 mm. in diameter, rounded or cuneate at base, abruptly apiculate-beaked, decidedly obcompressed, obtusely carinate ventrally by the suture, openly and shallowly sulcate dorsally, the rather stiffly papery, black- or partly white-strigulose valves inflexed as an incomplete septum (0.5) 1-1.6 mm. wide; dehiscence apical and downward through both sutures and the septum; ovules 17-31; seeds chestnut- brown, smooth, dull, 1.8-2.6 mm. long.