Jimsonweed (Datura stramonium)

Synonyms: Datura tatula

Common Names: Jamestown weed, mad apple, moonflower, stinkwort, thornapple

Description:

Jimsonweed (Datura stramonium) is a foul-smelling, trumpet-flowered annual in the nightshade family, native to Mexico and now found as a weed across the United States and much of the world [2]. MISIN tracks it because it's one of the most dangerous plants a homeowner is likely to encounter ? every part of it, especially the seeds, is highly toxic, and its hallucinogenic effects have led to serious and sometimes fatal poisonings [4][5].

Habit:

Jimsonweed is easiest to identify from July through September, when its large white-to-purple, trumpet-shaped flowers open ? often in the evening ? atop a stout, freely branching plant 2 to 5 feet tall [1][2]. Brush against the leaves or stems and you'll notice a strong, unpleasant odor, a reliable clue even when the plant isn't in flower [1][2]. By late summer, look for its most distinctive feature: an egg-shaped seed capsule covered in stiff spines, which splits into four sections when ripe [1].

At-a-glance cues:

1. Large trumpet-shaped flowers, 2 to 5 inches long, white to pale purple, often open in the evening [1][2]
2. Crushed or bruised leaves and stems give off a strong, unpleasant smell [1][2]
3. Leaves have large, irregular, jagged teeth along wavy margins [1][2]
4. Egg-shaped seed capsule covered in stiff spines, splitting into 4 sections when mature [1]

Leaves:

1. Arrangement: alternate [1]
2. Shape: ovate to oblong-elliptical [1][2]
3. Margin: irregular, with large triangular teeth along a wavy edge [1][2]
4. Size: 3?8 inches long, up to 6 inches wide [1]
5. Surface: hairless; releases a strong, unpleasant odor when crushed or bruised [1][2]

Stems:

1. Habit: stout, hollow, herbaceous, upright, freely branching [1]
2. Color: green or often tinged purple [1]
3. Hairs: smooth to only sparsely hairy [1]
4. Note: gives off a foul odor when damaged [2]

Flowers:

1. Color: white to pale purple [1]
2. Shape: large, funnel- or trumpet-shaped, 2?5 inches long, with 5 shallow lobes [1][2]
3. Arrangement: single flowers on short stalks arising where a leaf or branch meets the stem [1]
4. Bloom time: roughly July through September; individual flowers open in the evening and wilt by the next day [2]

Fruit and seeds:

1. Fruit type: egg-shaped capsule covered in stiff spines [1]
2. Size: 1?2 inches long [1]
3. Ripening: splits into 4 segments when mature [1]
4. Seeds: numerous flat, dark, kidney-shaped seeds [2]

Habitat:

Jimsonweed is native to Mexico and has since spread as a weed across the United States and through temperate and warm regions worldwide [2]. It grows in full sun in moist, well-drained soils, and turns up most often in disturbed ground ? roadsides, old fields, pastures, waste areas ? as well as in gardens and crop fields [1][2].

Reproduction:

Jimsonweed spreads only by seed [1]. On a home property, it most often arrives in contaminated soil, compost, hay, or bird seed. A single plant can produce a large number of spiny capsules over a season, each holding many seeds, so one unchecked plant can seed an area heavily by fall [1][2]. Once shed, jimsonweed seeds are known to lie dormant in the soil for years, only germinating when conditions ? like disturbed soil and warm temperatures ? are right [7]. Because of this seed-bank persistence, tilling or digging in a spot that once had jimsonweed can bring buried seed back to the surface and trigger a fresh flush of seedlings even long after the parent plants are gone [7]. Removing plants before the spiny seed capsules form in late summer is the key window for stopping that year's seed crop [1][2].

Impact and Damage:

Every part of jimsonweed, especially the seeds, is highly toxic to people, pets, and livestock if eaten. Its toxic compounds ? atropine, scopolamine, and hyoscyamine ? can cause dry mouth, dilated pupils, a racing heart, confusion, and hallucinations, with severe cases progressing to seizures, coma, or death; symptoms typically start 1 to 4 hours after ingestion and can last one to two days [4][5]. A documented 2019 outbreak in Uganda, traced to food contaminated with jimsonweed seeds, sickened close to 300 people and caused several deaths [4]. Handling the plant can also irritate skin, and dense stands in a yard, garden, or livestock area are a hazard for curious kids, pets, and grazing animals alike [2].

For natural area stewards and farmers, jimsonweed is also a serious agricultural weed. Research on jimsonweed growing alongside corn found that it competes for light and nutrients with the crop, slowing leaf growth and canopy development and reducing the number of kernels the crop's ears produce [3]. Because it thrives in the same disturbed, sunny ground favored by many other weeds, dense jimsonweed stands can also crowd out desirable vegetation while a disturbed area is recovering [2][3].

Economically, its presence in pastures and hayfields is a particular concern given its toxicity to grazing animals, and its competitive effect on row crops like corn adds to the cost of managing infested fields season after season [2][3].

Similar species:

A few close relatives and one well-known ornamental are easy to confuse with jimsonweed.

Sacred thornapple (Datura wrightii) is a close relative with flowers twice the size of jimsonweed's ? up to 8 or 9 inches long ? and its spiny seed capsule hangs downward from a nodding stalk rather than standing upright the way jimsonweed's does [8].

Downy thornapple (Datura inoxia) has even larger flowers than jimsonweed and is covered in soft, downy hairs that give the whole plant a grayish look, unlike jimsonweed's hairless, smooth-textured leaves. Its leaves also have smooth edges rather than jimsonweed's large jagged teeth [9].

Angel's trumpet (Brugmansia species) is a popular ornamental sold for gardens and containers that is often mistaken for jimsonweed because both have large trumpet flowers and extreme toxicity. The easiest way to tell them apart: angel's trumpet flowers hang downward and the plant grows into a woody, tree-like shrub, while jimsonweed's flowers point upward and the plant stays a soft-stemmed, green annual that dies back each year [10].

Monitoring and rapid response:

Signs to watch for:

1. Large white-to-purple trumpet flowers opening in the evening from July through September [1][2]
2. A strong, unpleasant smell when leaves or stems are bruised or crushed [1][2]
3. Spiny, egg-shaped seed capsules forming in late summer ? the last chance to act before that year's seed crop matures [1]

What you can do:

1. Wear gloves and hand-pull or dig up young plants while the soil is moist, ideally before the spiny seed capsules form in mid-to-late summer
2. Cut or mow larger plants at the base before flowering to prevent seed production, and repeat through the season since jimsonweed can keep sending up new growth
3. Bag and dispose of any plants with capsules already forming ? don't compost them, since the seeds can survive and the capsules may still ripen after cutting
4. Keep an eye on any spot that has grown jimsonweed before: because its seeds can lie dormant in the soil for years, soil disturbance from digging or tilling can trigger a fresh flush of seedlings even long after the original plants are gone
5. Natural area crews managing larger sites get the most value from repeat visits through the growing season to catch new seedlings before they flower, prioritizing removal before capsules form across the whole site rather than after

When to call a professional:

1. Large infestations in a pasture, hayfield, or livestock area, given the plant's toxicity to grazing animals
2. Dense stands that have already gone to seed across a wide area, where hand removal alone won't keep pace
3. Any situation where children or pets have regular access to an area with established plants
4. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. USDA Natural Resources Conservation Service, PLANTS Database. Datura stramonium L., jimsonweed. plants.sc.egov.usda.gov
2. North Carolina State University Extension Gardener Plant Toolbox. Datura stramonium. plants.ces.ncsu.edu
3. Karimmojeni H, Rahimian H, Alizadeh H, Yousefi A, Gonzalez-Andujar J, Mac Sweeney E, Mastinu A (2021). "Competitive Ability Effects of Datura stramonium L. and Xanthium orientale L. on the Development of Maize (Zea mays) Seeds." Plants 10(9):1922. semanticscholar.org
4. Mutebi RR, Ario AR, Nabatanzi M, Kyamwine I, Wibabara Y, Muwereza P, Eurien D, Kwesiga B, Bulage L, Kabwama S, Kadobera D, Henderson A, Callahan J, Croley T, Knolhoff AM, Mangrum J, Handy SM, McFarland M, Sam JF, Harris J, Zhu B (2021). "Large outbreak of Jimsonweed (Datura stramonium) poisoning due to consumption of contaminated humanitarian relief food: Uganda, March?April 2019." BMC Public Health 22:604. semanticscholar.org
5. Shebani A, Hnish M, Elmelliti H, Mohamed Abdeen M, Ganaw A (2021). "Acute Poisoning With Datura stramonium Plant Seeds in Qatar." Cureus 13(12):e20152. semanticscholar.org
6. Plants of the World Online, Royal Botanic Gardens, Kew. Datura stramonium L. powo.science.kew.org
7. Reisman-Berman O, Kigel J, Rubin B (1991). "Dormancy patterns in buried seeds of Datura ferox and D. stramonium." Canadian Journal of Botany 69(4):773?778. semanticscholar.org
8. USDA Forest Service. Sacred thorn-apple (Datura wrightii), Plant of the Week. fs.usda.gov
9. North Carolina State University Extension Gardener Plant Toolbox. Datura innoxia. plants.ces.ncsu.edu
10. Craven County Center, North Carolina Cooperative Extension. Datura vs. Brugmansia. craven.ces.ncsu.edu

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