Astragalus Preussii

Title

Astragalus Preussii

Author(s)

Rupert C. Barneby

Scientific Name

Astragalus preussii A.Gray

Description

179. Astragalus Preussii

Perennial but sometimes flowering the first season, rather coarse and robust, glabrous or nearly so below the inflorescence, the few hairs, when present, either filiform or scalelike, appressed, up to 0.1-0.5 mm. long, confined to the margins and midrib of the leaflets, the malodorous herbage green or yellowish-green, somewhat leathery; stems several, erect and ascending, (0.7) 1-3.5 dm. long, simple or few-branched below the middle, distally simple, or the flowering axils (in some populations) bearing a branchlet or spur inserted between petiole and peduncle; stipules 2-8 mm. long, the lowest ovate or broader than long, obtuse, papery or early becoming so, the upper ones ovate, deltoid, or lanceolate, herbaceous until late in the season, all decurrent around 1/3-7/8 the stem’s circumference; leaves (3.5) 4.5-18 cm. long, shortly petioled or the uppermost subsessile, with stiff rachis and (7) 11-25 rather distant leaflets 1.5-27 mm. long, these varying in shape from suborbicular-obcordate through oblong-obovate to linear-elliptic, narrowly lanceolate, or linear and acute, either all of one sort on a given plant, or dimorphic, those of the upper leaves of the narrower type; peduncles stout, (2) 3-15 cm. long, usually a little shorter than the leaf; racemes loosely (3) 4-16 (22)-flowered, the axis 1-23 cm. long in fruit; bracts membranous, pallid or purplish, ovate or lanceolate, 1.5-4 mm. long; pedicels ascending, straight, at anthesis (1) 1.5-2.8 mm., in fruit clavately thickened, (2) 2.5-5.5 mm. long; bracteoles nearly always 2, sometimes minute; calyx (6.4) 8.2-12.3 mm. long, thinly strigulose with black or mixed black and white hairs, the disc 1-2.9 mm. deep, the membranous, reddish or purplish, cylindric or subcylindric tube (5.1) 6-9.7 mm. long, (2.7) 3-4.8 mm. in diameter, the subulate teeth 1.3—2.6 mm. long; petals pink- or (when dried) bluish-purple, sometimes pallid but distally suffused with lilac- purple; banner recurved through ± 40°, rhombic-obovate or -oblanceolate, retuse or subentire at apex, (14) 16.5—24 mm. long, (6.4) 7.3—10.6 mm. wide; wings (12.6) 14.3—20.5 mm. long, the claws (5.8) 6.7—11.1 mm., the lance-oblong, obtuse, truncate, or obscurely emarginate, nearly straight blades (7.8) 8.7-11.3 mm. long, (1.5) 2.3—3.4 mm. wide; keel (11.1) 11.5—19 mm. long, the claws (5.6) 6.3-11.4 mm., the lunately half-elliptic or -oblanceolate blades 5.9-9.3 mm. long, 2.5-3.7 mm. wide, gently incurved through 60-90° to the blunt apex; anthers (0.6) 0.7—0.9 (0.95) mm. long; pod erect or narrowly ascending, stipitate or subsessile, the stipe up to 7 mm. long, the body narrowly to broadly oblong- ellipsoid or fusiform, inflated but hardly bladdery, (1.2) 1.5-3.2 (4) cm. long, (6) 7—13 mm. in diameter, straight or a trifle incurved, at base rounded, subtruncate, or obconic, abruptly contracted distally into a short, rigidly cuspidate beak, terete or a little compressed either laterally or dorsiventrally, sometimes shallowly sulcate ventrally, the sutures both prominent, the thinly fleshy, green or red-dotted, glabrous or minutely puberulent valves becoming stiffly papery or subcoriaceous, stramineous, not inflexed, the dorsal suture sometimes raised internally and simulating a vestigial septum; dehiscence apical, through the gaping beak; ovules (20-24) 26-44; seeds brown or orange-brown, smooth or nearly so, sometimes mottled with dull purple, 2.4-3.7 mm. long.