Datura stramonium L.

Common Jimsonweed

© DETenaglia

Family - Solanaceae

Habit - Taprooted annual forb.

Stems - Ascending to erect, to 1.2 m, branched, sparsely to moderately pubescent toward the tip with curled, nonglandular hairs.

	Stem.
© DETenaglia

Leaves - Alternate, simple, petiolate. Blades 5-20 cm long, ovate to narrowly ovate, angled or tapered to a sharply pointed tip, broadly angled to truncate at the base, the margins coarsely and sharply lobed and/or toothed, the surfaces (especially the undersurface) sparsely pubescent along and between the veins at maturity with minute hairs 0.1-0.4 mm long, more densely so when young.

	Pressed leaves.
© DETenaglia

	Leaf abaxial.
© SRTurner

Inflorescence - Solitary flowers, initially terminal, later produced in axils of branched nodes.

Flowers - Flower stalks 0.5-1.5 cm long. Calyces 3-5 cm long, tubular but strongly 5-angled to narrowly winged along the sides, finely hairy, the persistent base 4-7 mm long, usually reflexed at fruiting. Corollas 6-10 cm long, funnelform, white to partially pale to dark purplish-tinged or more uniformly light purple. Stamens with relatively long filaments, erect, positioned in a loose ring, not exserted, dehiscent longitudinally, light yellow to nearly white, usually hairy. Ovary 2-carpellate but appearing 4-locular, the style elongate, positioned at about the level of the anthers, green.

	Calyx.
© SRTurner

	Corolla.
© DETenaglia

© DETenaglia

	Stamens and style.
© DETenaglia

Fruits - Capsules 3-5 cm long, erect, more or less globose to more commonly broadly oblong-ovoid, the surface minutely hairy and densely prickly, the prickles 3-5 mm long. Seeds 3-4 mm in longest dimension, the surface finely pitted and often finely wrinkled, sometimes only faintly so, lacking a pair of dorsal grooves, more or less shiny, dark gray to black.

	Fruit.
© DETenaglia

	Dehiscent capsule and seeds.
© SRTurner

Flowering - May - October.

Habitat - Pastures, barnyards, fields, waste ground, cultivated areas, roadsides, railroads.

Origin - Native to tropical America, possibly the southwestern U.S.

Lookalikes - Other species of Datura, which are rare in Missouri.

Other info. - This toxic species can be found scattered throughout most of Missouri. It also occurs across most of the continental U.S., most frequently in the eastern half of the country. It is easily identified by its nearly glabrous stems, toothed leaves, large flowers, and spiked fruits. The entire plant is usually faintly to moderately malodorous.

Datura stramonium is packed with tropane alkaloids. These alkaloids are autonomic nervous system blocking agents. The alkaloid content is unpredictable and highly variable, depending on season, local environmental conditions and stages of plant development. This has lead to serious trouble for people attempting to use the plant as a recreational narcotic, and has lead to seizures, coma, and death as a result of unintentional overdose. By any rational definition the plant should be regarded as highly toxic.

The fragrant flowers of Datura are open at night, and in some species are pollinated by long-tongued nocturnal hawk moths. However, the flowers of D. stramonium are apparently mostly self-pollinated, despite being visited by both hawk moths and bees.

Photographs taken along Logan Creek, Ellington, MO., 8-1-04, and off Missouri Bottom Rd, St. Louis, MO., 8-7-05 (DETenaglia); also at Weldon Spring Conservation Area, St. Charles County, MO, 10-04-2012, and along the Katy Trail near Augusta, St. Charles County, MO, 9-20-2017 (SRTurner).