About Ammannia coccinea Rottb.
Ammannia coccinea Rottb. is a species of flowering plant in the loosestrife family. It goes by several common names: valley redstem, scarlet toothcup, and purple ammannia. This plant is native to most of the contiguous United States; it is not present in the Pacific Northwest and New England. It typically grows in moist areas, including riverbanks and pond margins, and it acts as a weed in some regions. It is an annual herb that can grow erect to heights close to one meter, or grow lying along the ground. Its leaves are linear in shape, reaching up to 8 centimeters in length, and range in color from green to deep red. Its inflorescence consists of a cluster of 3 to 5 flowers that grow from the leaf axils along the upper section of the stem. Each rounded flower has small rose to lavender petals that are a few millimeters long, plus protruding stamens that hold yellow anthers. The fruit it produces is a rounded capsule up to half a centimeter wide that holds many tiny seeds.