Herbs perennial, stems often fistulose, caulescent; caudex usually superficial, rarely subter­ranean. Hairs basifixed. Stems several to many. Stipules connate or distinct at distal nodes (except A. pomonensis ± distinct throughout). Leaves odd-pinnate, subsessile to petiolate; leaflets (11–)17–43. Racemes usually densely flowered, flowers horizontal, declined, or nod­ding, sometimes retrorsely imbricate. Calyx tubes campanulate or cylindric, sometimes gibbous proximally. Corollas greenish white, cream, or ochroleucous, keel apex sometimes faintly lilac-tipped, banner recurved through 35–50°, keel apex obtuse. Legumes eventually deciduous, sessile, gynophore sometimes present, loosely ascending, spreading, or declined, obliquely ovoid, semi-ovoid, ovoid-lenticular, obovoid, rhombic-ellipsoid, or ovoid-ellipsoid, straight or slightly curved, usually bladdery inflated, sometimes barely inflated, or laterally or dorsiventrally compressed, unilocular. Seeds (2 or)3–12 or 12–55.

Distribution

California, nw Mexico.

Discussion

Species 5 (5 in the flora).

Section Densifolii is complex, composed of three subsections. Distribution is mainly in or near coastal central to southern California and Baja California.

The subsections are: subsect. Crotalarii M. E. Jones (Astragalus curtipes, A. nuttallii, A. pomonensis); subsect. Pycnostachyi (Rydberg) Barneby (A. pycnostachyus); and subsect. Oxyphysi (M. E. Jones) Barneby (A. oxyphysus).

Selected References

None.

Lower Taxa

Astragalus curtipes, Astragalus nuttallii, Astragalus oxyphysus, Astragalus pomonensis, Astragalus pycnostachyus