Monographs Details: Astragalus lentiginosus var. maricopae 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 - Perennial but apparently not of long duration, appearing glabrous, the stramineous or purplish stems truly so, the leaf-rachises and inflorescences thinly strigulose with subappressed, pale or black hairs up to 0.5-0.8 mm. long, the herbage green or subglaucescent; stems several, incurved-ascending, 3-4 dm. long, simple or spurred at 1-3 nodes preceding the first peduncle; leaves (4) 6-16 cm. long, with 17-25 ovate, broadly oval, oblong-elliptic, or (in some lower leaves) obovate-obcordate, obtuse and mucronulate or emarginate, flat, thick-textured leaflets (3) 5-22 mm. long; peduncles stout, erect, 5-14 cm. long, shorter than or equaling the leaf; racemes loosely 13-30-flowered, the axis (3) 5-20 cm. long in fruit; calyx 7.2-8.6 mm. long, thinly black- or partly white-strigulose, the tube 5.6-6.4 mm., the teeth 1.6-2.6 mm. long; petals ochroleucous, immaculate; banner 15-16.5 mm. long; wings 12.8-14.2 mm., the blades 7.6-9 mm. long; keel 11.2-12 mm., the blades 5.8-6.3 mm. long, 2.6-3 mm. wide; pod ascending, narrowly oblong- or linear-ellipsoid, very slightly incurved, 2-3 cm. long, 3.7-5 mm. in diameter, not inflated, cuneate at base, contracted distally into a narrowly triangular-acuminate, unilocular beak 3-5 mm. long, the body subterete, carinate ventrally by the prominent suture, the somewhat fleshy, green, glabrous valves becoming leathery or stiffly papery, stramineous, almost smooth, the septum narrow but complete; ovules 22-26.
Distribution and Ecology - Stony washes and roadsides, 1100-2300 feet, known only from the middle Gila Valley in Maricopa County (Cave Creek; Fish Creek; Tempe), Arizona.— Map No. 131.—March to May.
Discussion:The var. maricopae is intermediate in some respects between var. yuccanus and var. Wilsonii, which are found short distances to the north and west in Arizona. The slenderly fusiform or subcylindric, uninflated pod is like that of var. Wilsonii, but the long, open racemes of somewhat smaller, cream-colored flowers distinguish it at a glance. The size and color of the flowers are more nearly in agreement with var. yuccanus, but they average a trifle larger and the petals are more strongly graduated. The ovule-number is nearly the same in var. yuccanus and var. maricopae, but the pod of the former is bladdery-inflated. The variety differs from var. australis, the pod of which is sometimes little inflated, in its ochroleucous petals and very narrow, terete fruit.
Arizona United States of America North America