Plants annual or winter-annual, ephemeral, very slender, (2–)3–10(–23) cm, sparsely strigulose, hairs basifixed; taproot slender. Stems erect or ascending, sparsely strigulose. Leaves 1.5–5 cm; stipules 1–2.5 mm, sub­membranous becoming papery; leaflets 5–9, blades cuneate-obovate to narrowly cuneate, 2–10 mm, apex retuse, surfaces sparsely strigulose abaxially, glabrous adax­ially. Peduncles ascending becoming declined or divar­icate, 2–7 cm. Racemes 2–7-flowered, flowers spreading to declined; axis 0.2–1(–1.3) cm in fruit, scarcely elongating; bracts 0.7–1.2 mm; bracteoles 0. Pedicels 0.4–2.2 mm. Flowers 8.9–12 mm; calyx 2.8–4 mm, strigulose, tube 2.1–2.6 mm, lobes triangular to sub­ulate, 0.6–1.4 mm; corolla whitish, banner and keel tips purple; banner recurved through 20°; keel 7.4–9.1 mm, apex round. Legumes horizontal or declined, green or faintly brown-mottled becoming brownish, incurved, crescentic and linear, obscurely 3-sided compressed, falling before splitting, dehiscent on ground, 17–25 × (1.6–)2–3.1 mm, thinly fleshy becoming stiffly papery, base and apex acuminate, strigulose; bearing seeds near middle; gynophore pseudostipitate, slender, 1.4–2.5 mm. Seeds 6–12. 2n = 22.

Phenology: Flowering Apr–May.
Habitat: Grassy slopes, especially on thin volcanic clay substrates moist in springtime.
Elevation: 90–200 m.

Distribution

• Generated Map
• Legacy Map

Calif.

Discussion

Astragalus claranus occurs in the North Coast Ranges in Napa and Sonoma counties; it is sometimes confused with A. tener var. ferrisiae. Both taxa are pseudostipitate, but A. claranus has, in addition, a slender gynophore from which the fruit disarticulates. No other species has both a pseudostipe and a gynophore (R. C. Barneby 1964). The keel also exceeds the wings in A. claranus, but not in var. ferrisiae (A. Liston 1990).

Selected References

None.

Lower Taxa

None.