Astragalus sect. Desperati

Herbs perennial (sometimes flowering as annual), tuft-forming, acaulescent, subacaulescent, or short-caulescent; caudex superficial. Hairs basifixed (incipiently malpighian in A. cottamii, sometimes shortly malpighian in A. monumentalis). Stems obsolete or few. Stipules connate or distinct. Leaves odd-pinnate, petiolate; leaflets (3–)7–19(or 21). Racemes loosely flowered or subcapitate, flowers ascending, spreading, or declined. Calyx tubes campanulate or cylindric. Corollas purple, pink-purple, whitish tipped with purple, or ochroleucous, often purple-veined, banner recurved through 40–45°, keel apex round to narrowly deltate. Legumes deciduous, sessile, gynophore short or absent, declined, deflexed, spreading, or ascending (humistrate), obliquely ovoid to narrowly oblong-ellipsoid or linear-lanceoloid, straight or incurved, dorsally or 3-sided compressed, unilocular, subunilocular, or bilocular. Seeds 8–31.

Distribution

w United States.

Discussion

Species 7 (7 in the flora).

Section Desperati consists of two subsections, with distribution on sandstone rimrock in northern Arizona, western Colorado, northwestern New Mexico, and southeastern Utah. The subsections are: subsect. Desperati Barneby (Astragalus barnebyi, A. desperatus, A. equisolensis); and subsect. Naturitenses Barneby (A. cottamii, A. deterior, A. monumentalis, A. naturitensis).

Selected References

None.

Lower Taxa

Astragalus barnebyi, Astragalus cottamii, Astragalus desperatus, Astragalus deterior, Astragalus equisolensis, Astragalus monumentalis, Astragalus naturitensis