Jamestown weed is often more commonly known as "jimsonweed" or simply "jimpson". It is a
poisonous annual plant (
Datura stramonium) in the
nightshade family (
Solanaceae). It has stinky leaves and white trumpet-shaped blooms and is the source of many useful
alkaloids, including
atropine,
hyoscine and
hyoscyamine.
Reputedly, the early settlers in Jamestown, Virginia discovered the toxic effects of the plant when a cook mistakenly collected several of them to make a side dish of greens to a meal.
From the science dictionary at http://biotech.icmb.utexas.edu/.