Astragalus lentiginosus var. mokiacensis
Rev. N.-Amer. Astragalus, 126. 1923.
Plants perennial, 20–60 cm, herbage green or subglabrescent. Leaves 3–10(–13) cm; leaflets (7 or)9–17(–21), blades broadly obovate-obcordate, lanceolate, elliptic, or suborbiculate-obcordate, 5–13(–19) mm, apex emarginate or retuse to truncate, adaxial surface glabrous. Peduncles 4–11(–14) cm. Racemes loosely 12–20-flowered; axis elongating, 3.5–18(–22) cm in fruit. Flowers (10–)14–18(–19) mm; calyx 5–8(–9.2) mm, tube (3.5–)4–6.5 mm, lobes 1–2(–2.7) mm; corolla pink- to red-purple, usually with pale or white wing tips. Legumes dehiscent on plant, usually ascending-erect to ascending, rarely spreading, green becoming stramineous, usually ± straight to incurved, rarely decurved, oblong-ellipsoid, not or scarcely inflated, slightly turgid, 14–28(–32) × 4.5–6.5 mm, ± bilocular, somewhat fleshy becoming leathery or stiffly papery, glabrous or minutely pubescent; beak 3–4 mm, unilocular. Seeds (22–)25–36. 2n = 22.
Phenology: Flowering Mar–Jun.
Habitat: Limestone on outcrops and gravel, on basaltic or granitic gravel and/or outcrops, with Hymenoclea, bursage, Joshua tree, Larrea, and Ferocactus.
Elevation: 700–1800 m.
Distribution
Ariz., Nev., Utah.
Discussion
The placement of var. mokiacensis has challenged generations of botanists. R. C. Barneby (1945) regarded var. mokiacensis as part of the lentiginosus complex but later (Barneby 1964) recognized it as a species within sect. Preussiani. In Washington County in Utah, var. mokiacensis has been consistently confused with var. palans. S. L. Welsh (2007) extensively discussed problems revolving around interpretation and distinction of var. mokiacensis. J. A. Alexander (2005) considered the taxon to be best recognized at the species level, as A. mokiacensis, the persistent fruit being otherwise unknown in A. lentiginosus. Alexander also presented a key to similar taxa and to minor variants within A. mokiacensis. As recognized here, the variety is found in Washington County in southwestern Utah, northwestern Mohave County in Arizona, and eastern Clark County in Nevada.
Selected References
None.