Astragalus leucolobus
Zoë 4: 270. 1893.
Plants subacaulescent or shortly caulescent, 5–15 cm, villous-villosulous, hairs basifixed; from superficial caudex. Stems erect to sprawling, to 7 cm, internodes often shorter than stipules, villous-villosulous. Leaves (1.5–)2.5–9 cm; stipules 2–10 mm, submembranous; leaflets (7–)11–19, often crowded, blades elliptic to broadly obovate, 3–13 mm, apex obtuse, acute, or shortly acuminate, surfaces villous. Peduncles incurved-ascending, decumbent in fruit, (3–)5–13 cm. Racemes 5–13-flowered, flowers ascending; axis (0.5–)2–8 cm in fruit; bracts 2.5–8 mm; bracteoles 2. Pedicels 0.8–2.2 mm. Flowers 16–18.5 mm; calyx purplish, usually cylindric, sometimes cylindro-campanulate, 8.2–10.7 mm, villosulous, tube 6.6–8.9 mm, lobes subulate or subulate-triangular, 1.5–3.5 mm; corolla pink-purple or pallid; banner recurved through 40°; keel 14.3–16.8 mm. Legumes ascending (humistrate), gently incurved, obliquely lanceoloid-oblong, obcompressed to 3-sided compressed, (13–)15–25 × 4.5–9 mm, bilocular, fleshy becoming stiffly leathery, densely villous-tomentulose, hairs to 1 mm; inflexed, especially proximal 1/2, as a narrow, complete septum. Seeds 18–24.
Phenology: Flowering May–Jul.
Habitat: Dry pine woods, gravelly knolls with sagebrush, stony lakeshores in pine belt.
Elevation: 1500–2800 m.
Distribution
Calif.
Discussion
Astragalus leucolobus, known from the interior mountains of southern California, is similar to A. purshii in fruit but differs in its shorter pubescence that scarcely hides the surface of the fruit. D. Isely (1998) provided keys to distinguish between flowering specimens of A. leucolobus and contiguous or partially sympatric A. purshii vars. lectulus and tinctus.
Selected References
None.