The Carlisle Mosquito Online

Friday, February 8, 2008


Biodiversity Corner Jimsonweed

Jimsonweed pods are visible now, in winter. (Photo by Kay Fairweather)

Many plants are easily identified by distinctive seed pods which last through the winter. Milkweed and Queen Anne's Lace fall into this category as does this week's topic, the Jimsonweed. It is not a giant among plants, but it is stinky and poisonous and has powers that could bring down an otherwise strong and unsuspecting patriot.

Name. There was a famous incident in Jamestown, Virginia, in 1676 when British soldiers who were sent to put down a rebellion fell ill from eating a local plant. The plant became known as Jamestown weed and over time the name morphed into Jimsonweed. The scientific name is Datura stramonium, and it also has several other common names including Thorn Apple, Mad Apple and Stink Weed. It is a member of the Solanaceae family which includes food plants like potatoes, peppers, tomatoes and eggplants and also poisonous plants like nightshades and dubious ones like tobacco.

When and where seen. You will find Jimsonweed in rich soils and open areas like fields, pastures and barnyards. On February 4, I found some sticking up through the snow along the East Farm Trail in Great Brook Farm State Park. I also found some in flower in the dung pit opposite the Cranberry Bog, as late as October 12 last year.

Distinguishing characteristics. This time of year you can recognize the plant by its thorny seed pods which are just under two inches long. The pods split into four segments and release small black deadly poisonous seeds. The old stalks along East Farm trail are about three feet tall, but the plant is known to grow to five feet. It flowers from July to October with an elongated white funnel-shaped flower on a short stalk. The flowers can also be pale violet. The leaves are large, up to eight inches long and coarsely toothed.

The Jimsonweed's flower, which is white, appears in July through October. (Photo by Kay Fairweather)

Toxicity. The plant is poisonous to both livestock and humans. Livestock will only graze it if they have little choice. They are most likely to be poisoned by it from contaminated feed. The active ingredients are the alkaloids atropine, scopolamine and hyoscyamine. Datura has been used medicinally and in Native American ceremonies, but it is not something to experiment with. The fatal dose is too close to the therapeutic dose.

Sources. Wyman's Gardening Encyclopedia, Donald Wyman; Common Wildflowers of the Northeastern United States, Carol H. Woodward and Harold William Rickett; Lauren Brown, Weeds in Winter; Cornell University Dept. of Animal Science at (search on jimson).

Submissions for the Biodiversity Corner are encouraged from everyone. You can write the column or tell me what you saw and I will write it. The organism doesn't have to be unusual. The only requirements are that it exists in the wild and was seen in Carlisle. Send a note to

2008 The Carlisle Mosquito