Desert thorn-apple, small datura

Datura thomasii Torrey

Herbs annual or short-lived perennial, to 10 dm. Stems usu­ally hairy, sometimes glabrous. Leaf blades ovate, to 18 × 16 cm, margins entire or dentate, abaxial surface hairy, adaxial surface glabrous. Flowers: calyx hairy along veins, tube cylin­dric, 5-toothed; corolla white throat with purple ring, trumpet-shaped, 8–15 cm, acuminate lobes alternating with larger lobules. Capsules pendent, regularly dehisc­ing by 4 valves, pericarp dry, hairy, with prickles to 3.2 cm; calyx remnant accrescent (sometimes reflexed). Seeds black, 3–4.5 mm, convex marginal ridge absent, testa rugose; caruncle present. 2n = 24.

Flowering Mar–Oct. Streamsides, irrigation ditches, road and trail margins, waste places, desert shrublands, grasslands, pinyon-juniper-oak woodlands; 0–600(–1800) m; Ariz., Calif.; Mexico; Central America; introduced nearly worldwide.

Outside of its typical flowering period, Datura discolor flowers sporadically after rains.