Desmodium arizonicum
Proc. Amer. Acad. Arts 20: 363. 1885.
Herbs, perennial. Stems erect or ascending, usually striate, sparsely branched, 20–80 cm, pubescent. Leaves trifoliolate; stipules caducous, narrowly ovate, 6–8 mm; petiole 1–5 mm; leaflet blades narrowly oblong-elliptic to linear, apex acute, surfaces villosulous; terminal blade 40–60 × 4–10 mm, length 3.5–10 times width. Inflorescences usually unbranched; rachis uncinate-puberulent; primary bracts caducous, broadly ovate, 4.5–5.5 mm. Pedicels 8–15 mm. Flowers: calyx 3 mm, uncinate-puberulent, lobes pubescent, tube 1.2 mm; abaxial lobes 2 mm, lateral lobes 1.5 mm; corolla blue-purple, 5–6 mm. Loments: sutures undulate abaxially, crenate adaxially; connections adaxial, 1/3 as broad as segments; segments (2 or)3–5, semiorbiculate, 4–5(–6) × 4 mm, rounded abaxially, convex adaxially, uncinate-puberulent; stipe 1–2 mm. 2n = 22.
Phenology: Flowering summer–fall.
Habitat: Oak-juniper or pine woodlands, canyons, roadsides.
Elevation: 1700–2500 m.
Distribution
Ariz., N.Mex., Mexico (Baja California, Chihuahua, Sinaloa, Sonora, Tamaulipas).
Discussion
In the flora area, Desmodium arizonicum is known from southeastern Arizona and adjacent New Mexico.
Selected References
None.