Ask Mr. Smarty Plants

One possibility is the Common Jimsonweed or Thorn Apple (Datura wrightii) which according to the Missouri Department of Conservation is described as ... Tall, branching, leafy, rank-smelling annual, often with purple stems. Flowers 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; white or light violet, or white with a violet throat. Flowers open in the evening with a strong perfume and close in early morning. Blooms May–October. Leaves alternate, on petioles, deeply lobed with teeth, to 4 inches long. Fruit an ovoid, spiny capsule to 2 inches long, upright, splitting open by 4 valves, spilling many flat, black seeds. Height: to 5 feet.

Occurs in pastures, barnyards, fields, roadsides, railroads, and waste or cultivated land. A native of tropical America, jimsonweed was introduced and has naturalized in much of the United States. Though it and its relatives have a long history as medicinal plants, with many varied uses, only a slight overdose can kill a person. Like most members of the nightshade family, common jimsonweed is poisonous, causing hallucinations. The seeds are particularly toxic. It is a troublesome weed of crop fields, and livestock can be poisoned by it. Handling the plant can cause skin irritation in some people.

Sphinx moths pollinate the goblet-shaped flowers, which open around midnight and close by early morning. Although toxic to mammals, the plant is eaten by several types of insects