Jimsonweed Identification Guide

Key Identifying Features

Jimsonweed (Datura stramonium), also called thornapple, is a tall, bushy, strongly ill-smelling annual in the nightshade family and is highly poisonous. Recognize it by its large white to pale violet trumpet-shaped flowers, its spiny, egg-shaped seed capsules, and its big, coarsely toothed leaves with a rank odor when crushed.

• Stout, branching annual, often 2 to 5 feet tall
• Large trumpet flowers, 2.5 to 5 inches long, white or lavender
• Spiny (thorny) egg-shaped seed pods about the size of a walnut
• Large, jaggedly toothed, foul-smelling leaves
• Smooth stems often tinged purple

Leaves & Stems

Leaves are large (up to 8 inches), broadly oval, and coarsely and irregularly toothed or lobed, with pointed teeth giving a jagged, almost oak-like or maple-like outline. They are dark green, thin, and emit a rank, unpleasant smell when bruised. The stems are stout, smooth, hollow, and freely branching, frequently flushed purple, especially on the var. tatula form. The plant has a bushy, somewhat sprawling habit.

Flowers & Fruit

The flowers are erect, trumpet- or funnel-shaped, 2.5 to 5 inches long, with a long tube flaring into five (sometimes ten) shallow pointed lobes. They are typically white, sometimes washed with violet or pale purple, and open in the evening, often fragrant at dusk and pollinated by moths. Each flower develops into a hallmark hard, egg-shaped capsule densely covered in stiff spines, which splits into four parts to release numerous flat, dark seeds. Flowering and fruiting span summer into fall.

How to Tell It Apart from Look-Alikes

• Henbane (Hyoscyamus niger): Has dull yellow, purple-veined flowers and lidded urn capsules rather than white trumpets and spiny pods.
• Moonflower / ornamental Datura and Brugmansia: Brugmansia (angel's trumpet) has huge pendant (hanging) flowers on a woody shrub/tree, whereas jimsonweed's trumpets point upward on a herbaceous annual.
• Cocklebur: Has bur-like fruits but inconspicuous flowers and rough, non-trumpet leaves.

The pairing of upright white/violet trumpet flowers with spiny egg-shaped pods and a rank smell is diagnostic.

Where You'll Find It

Jimsonweed favors rich, disturbed soils in full sun: barnyards, feedlots, cultivated fields, gardens, roadsides, waste ground, and overgrazed pastures. Widely naturalized across North America and much of the world, it often appears where soil has been churned and fertilized.

Safety: All parts, especially the seeds, contain dangerous tropane alkaloids (atropine, scopolamine, hyoscyamine). Ingestion can cause severe poisoning or death. Never eat any part, keep it away from children and livestock, and wash hands after handling.

Quick ID Checklist

• Bushy annual, 2 to 5 ft, foul-smelling
• White or violet upright trumpet flowers, 2.5 to 5 in
• Spiny, egg-shaped seed pods (thornapples)
• Large, jaggedly toothed leaves
• Smooth, often purple-tinged hollow stems
• Highly poisonous; rich disturbed soils