Astragalus neomexicanus

Plants caulescent, 10–35(–40) cm, strigulose to pilose, hairs basifixed; from superficial caudex. Stems decumbent to incurved-ascending, strigulose to pilose. Leaves (5–)8–23 cm; stipules (3–)6–12 mm, submembranous; leaflets (19–)23–39(–43), blades usually lanceolate-ovate or rhombic-elliptic, sometimes oblong-obovate, (3–)5–20 mm, apex usually acute or subacute, sometimes obtuse or emarginate, surfaces strigulose to pilose abaxially, glabrescent or glabrate adaxially. Peduncles incurved-ascending, (5–)6–15 cm. Racemes (10–)12–24-flowered, flowers nodding, secund, retrorsely imbricate; axis (3–)5–12 cm in fruit; bracts 3–10 mm; bracteoles 0–2. Pedicels 1–3.5 mm. Flowers 15.7–19.2 mm; calyx cylindric to broadly campanulate, 9.6–13 mm, strigulose, tube 6.8–9.4 mm, lobes lanceolate or triangular-lanceolate, 2.8–4.4 mm; corolla dull pinkish lavender, greenish purple, or bright magenta-purple; banner recurved through 45°; keel 11.3–12.7 mm. Legumes loosely pendulous (from ascending peduncles) or ascending (and humistrate), stramineous then brownish, gently incurved, obliquely oblong-ellipsoid, obcompressed, (17–)20–33 × (4–)7–11 mm, ± unilocular, fleshy becoming leathery, strigulose. Seeds 28–33. 2n = 22.

Phenology: Flowering late May–Oct.
Habitat: Dry, gravelly banks, stony hillsides, talus under cliffs, valley bottoms, roadcuts, in pinyon-juniper, ponderosa pine, or mixed conifer forests.
Elevation: 2000–2600 m.

N.Mex.

Discussion

Astragalus neomexicanus is restricted to the mountains of southern Lincoln and northern Otero counties. It is somewhat isolated in sect. Argophylli. R. C. Barneby (1964) observed that it seemed to occupy a position intermediate in some notable technical characters between sects. Argophylli and Gigantei, suggesting that it may represent a taxon selected and stabilized from progeny of A. giganteus × A. tephrodes.

Selected References

None.

Lower Taxa