black nightshade

this is solanum americanum; it is of the family solanaceae.

this small flower begins to turn purple-ish black as it progress to becoming a berry, whose color is black. this can be seen here. as will all species of night shade, this plant contains a poison called solamine, whose action affects digestion and manifest certain neurological phenomenon, including paralysis and hallucinations. a lethal does for humans can occur at as little as 3 mg. it would appear that the common potato also harbors this poison, though it is only present under certain conditions.

solanum americanum blooms from june to november.