Fierce thorn-apple

Herbs annual, to 10 dm. Stems puberulent, sometimes glabres­cent. Leaf blades broadly ovate, to 13 × 8 cm, margins usually sinuate-dentate, sometimes pin­nately lobed, surfaces glabres­cent. Flowers: calyx with min­ute pubescence along veins, tube cylindric, 5-toothed; corolla white, trumpet-shaped, 4–6 cm, acuminate lobes alternating with sinuses. Capsules erect, dehiscent by 4 valves, pericarp dry, sparsely hairy, with prickles unequal, some 15+ mm, proximals shorter than distals; calyx remnant not accrescent. Seeds black, 4–4.5 mm, convex marginal ridge absent, testa rugose; caruncle absent. 2n = 24.

Flowering Jun–Sep. Cultivated fields, irrigation ditches, road and trail margins, waste places; 0–150 m; introduced; Ala., Ark., Calif., Ga., Nev., N.Y., N.C., Pa.; occasional nearly worldwide.

The origin and native status of Datura ferox is unresolved, although China has been cited as the coun­try of origin since Linnaeus. The most extensive phyto­geographic distribution of this species is in north­ern Argentina. Its association with ship ballast and seed stock of monocultural crops may explain its local abun­dance when introduced.