Common jimsonweed is a tall, branching, leafy, rank-smelling annual nonwoody plant, often with purple stems.
The flowers are funnel-shaped, pleated, and swirled, with 5 sharply pointed lobes, to 5 inches long. The tube emerges from a green calyx less than half the length of the corolla; the corolla is white or light violet, or white with a violet throat. The flowers open in the evening with a strong perfume and close in early morning.
Blooms May–October.
The leaves are alternate, on petioles, deeply lobed with teeth, to 4 inches long.
The fruit is an ovoid, spiny capsule to 2 inches long, upright, splitting open by 4 valves, spilling many flat, black seeds.
Similar species: Only one other species of Datura is likely to be encountered in Missouri:
- Hairy jimsonweed (Datura wrightii), also called sacred thorn-apple or angel's trumpet, is uncommon and occurs mostly in the southern half of the state. Its leaves (especially the undersides) and stems are distinctively hairy, it has larger, showier flowers (to 6 inches long), and its leaves, though wavy-edged, are not clearly toothed. It, too, lives along railroads and roadsides and in other open, disturbed areas.
Height: to 5 feet.
Scattered nearly statewide.
Habitat and Conservation
Occurs on banks of streams and rivers; also in farmyards, pastures, fallow fields, margins of crop fields, railroads, roadsides, and open, disturbed areas.
The native range is uncertain; apparently, it is native of tropical America, and perhaps to the southwestern United States. Jimsonweed was introduced and has become naturalized in much of the United States. It has been introduced and now occurs in tropical and warm-temperate regions globally.
Status
Nonnative, naturalized plant, often considered a weed. Toxic if eaten. Can cause skin irritation when handled.
Taxonomy: botanists have been rearranging and renaming the various species in this genus, using DNA analysis.
Human Connections
Like most members of the nightshade family, common jimsonweed is poisonous, causing hallucinations and death. The seeds are particularly toxic. Although jimsonweed and its relatives have a long history as medicinal plants, with many varied uses, even just a slight overdose can kill a person.
Jimsonweed is a troublesome weed of crop fields, and livestock can be poisoned by it.
Handling the plant can cause skin irritation in some people.
There have been documented instances where jimsonweed leaves were inadvertently included with spinach harvests, causing illness in the people who had consumed them.
The genus name, Datura (pronounced dah-TOO-rah), is from Hindi and ultimately Sanskrit origins; it means "white thorn-apple." The common name "jimsonweed" is derived from the name "Jamestown weed." In the late 1600s, English soldiers in Jamestown, Virginia, ate the leaves and were reportedly insane for a week and a half after that.
Despite their toxicity, these large, fragrant, night-blooming flowers are lovely, and several species are cultivated as garden specimens.
In the 1930s, modernist artist Georgia O'Keeffe painted several famous, huge, close-up portraits of jimsonweeds. These were plants that grew near her home in New Mexico and were of a different species than Missouri's. Today, her Jimson Weed paintings are valued at tens of millions of dollars.
Several species of Datura occur in North America, particularly in the southwest. You might have seen them if you visited the Grand Canyon, where bats pollinate them by moonlight. A close relative, a tropical woody plant with large, orange, fragrant, downward-facing flowers, called "angel's trumpet" (genus Brugmansia), is often grown as a potted plant.
Ecosystem Connections
Sphinx, or hawk moths visit the goblet-shaped flowers, which open around midnight and close by early morning. Hummingbirds visit the flowers, too. Apparently, most flowers of this species are self-pollinating, however.
Although toxic to mammals, the plant is eaten by several types of insects, notably tomato hornworm and Carolina sphinx moth (tobacco hornworm) caterpillars, which eat various members of the potato/nightshade family. The toxins in the plant's tissues generally function as a defense against herbivory. However, some insects have evolved to eat these toxic plants; by doing so, the insects become toxic themselves, therefore protected from their own predators. As winged adults, these hornworms (sphinx or hawk moths) are quite likely to visit the flowers of these same plants.
Some types of bats drink nectar from and pollinate Datura species, especially in the U.S. southwest.
