Astragalus douglasii var. perstrictus
Bull. S. Calif. Acad. Sci. 31: 65. 1932. (as perstricta)
Stems erect or stiffly ascending, 40–100 cm. Leaflets (11 or)13–19, blades narrowly elliptic, lanceolate-oblong, or narrowly obovate, 7–25 mm, apex obtuse or truncate-emarginate and apiculate. Peduncles erect, 7–13 cm. Racemes 12–20-flowered; axis 4–10 cm in fruit. Flowers: calyx 4.1–5 mm, sparsely strigulose, tube (2.5–)2.9–4.3 mm, lobes broadly triangular or triangular-subulate, 0.7–1.1 mm; corolla banners 8.5–10 × 7–8.4 mm. Legumes not humistrate, (35–)40–60 mm, strigulose; seed-bearing flange 1 mm wide. Seeds (48–)58–67. 2n = 22.
Phenology: Flowering late Apr–Jun.
Habitat: Stony hillsides, gravelly or sandy flats, decomposed granitic soils, open oak woodlands.
Elevation: 900–1300 m.
Discussion
Variety perstrictus is restricted to southeastern San Diego County (and probably adjacent Baja California) and is more or less intermediate between two other local taxa, Astragalus douglasii var. parishii and A. oocarpus. R. C. Barneby (1964) suggested possible amphidiploidy, but R. Spellenberg (1976) reported 2n = 22 in all varieties of A. douglasii and also in A. oocarpus.
Selected References
None.