28. Oxalis drummondii A. Gray, Smithsonian Contr. Knowl. 5(6): 25. 1853.
Drummond's wood-sorrel Drummond's wood-sorrel
Oxalis vespertilionis Torrey & A. Gray, Fl. N. Amer. 1: 679. 1840, not Zuccarini 1834; O. amplifolia (Trelease) R. Knuth
Herbs perennial, acaulous, rhizomes and stolons absent, bulb solitary; bulb scales 3-nerved, <margins villous-ciliate on distal 1/3–1/2>. Leaves basal; petiole 5–16 cm; leaflets 3, green, sometimes with red splotches in irregular medial band adaxially, obtriangular to obcordate, (6–)14–34 mm, lobed 1/4–4/5 length, <lobes apically convex to nearly truncate>, surfaces glabrous, oxalate deposits absent. Inflorescences umbelliform cymes, 3–10-flowered; scapes (7–)11–23 cm, glabrous. Flowers distylous or rarely homostylous; sepal apices with 2(–6) orange, <linear, thickened, apically confluent> tubercles; petals white to pale green proximally with green veins, pink to violet or purple-violet distally, (8–)15–23 mm. Capsules cylindric, 4–12 mm, hairy. 2n = 14.
Flowering Mar–Nov. Sandy-gravelly soils, limestone soils, disturbed areas, prairies, limestone hills, open woodlands, chaparral; 20–300 m; Tex.; Mexico (Coahuila, Nuevo León, San Luis Potosí, Tamaulipas).
Oxalis drummondii is found in the flora area in central and southern Texas. Reports of this species from Arizona, New Mexico, and trans-Pecos Texas are based on misidentifications of O. latifolia and O. metcalfei.