Virginia Tech Weed Identification Guide

Jimsonweed: Datura stramonium

Weed Description:   An erect summer annual with large white to purple flowers and a distinctive odor. Primarily a weed of agronomic crops found throughout most of the US except for the Northwest.
Seedling:   Cotyledons thick, without hairs, long and linear in outline (2 inches long, 6 mm wide). Cotyledons also have a clearly evident midvein. The stem below the cotyledon (hypocotyl) is initially maroon in color toward the base, eventually becoming maroon throughout. First true leaves have a continuous, untoothed margin (entire), while later leaves are toothed.
Leaves:  Large, 3-8 inches long, 6 inches wide, ovate, without hairs, on long stout petioles. Margins with a few large triangular teeth. Leaves emit an unpleasant odor, especially when touched.

Roots:  Thick and extensively branched taproot system.

Fruit:  An egg-shaped capsule (1-2 inches long), covered with stiff prickles, and splitting into 4 segments when mature.
Flowers:  Large, 2-5 inches long, white to purple in color and funnel-shaped. Individual flowers occur on short stalks (pedicels) that arise from leaf or branch axils. Sepals enclose the lower part of the flower.
Stems: Very stout, hollow, smooth, branching, green or more often purple, with inconspicuous hairs.
Identifying Characteristics: Plants with large conspicuous flowers and fruit. Also, the distinctive odor of jimsonweed helps in identification. The cotyledons of Common Cocklebur (Xanthium strumarium) might be confused with those of Jimsonweed. However, Common Cocklebur cotyledons lack the distinctive midvein and are generally larger and less linear than those of Jimsonweed.