This species is also called the spreading or prairie nightshade, the cut-leaved nightshade, and wild tomato.
The three-flowered nightshade is a low spreading annual, widely branching, sometimes forming a heavy flat mat from one to two feet in diameter. The leaves are oblong, with seven to nine lobes. The white flowers are arranged in groups of three. The berries are nearly twice the size of the following species, being one-half inch, or more, in diameter. They retain their green colour even when ripe. They are usually in groups of three. The plant blooms from July to September.
This native plant is found as a garden weed in Eastern Canada. It is becoming common on the prairies from Manitoba to Alberta.
The poisonous principle of this species has not yet been determined, but it is probably similar to the preceding. Experiments carried on by Chesnut proved that the berries were poisonous to guinea pigs. Chesnut and Wilcox say, "A single complaint of the poisoning of cattle by the fruit was sent to this department from Nebraska, and rabbits inoculated with the juice of the berries from that State were badly poisoned."