Aconogonon phytolaccifolium is a species of flowering plant in the knotweed family known by the common name Poke knotweed .
Aconogonon phytolaccifolium is native to the western United States: California, Oregon, Washington, Nevada, Idaho, and Montana.
Aconogonon phytolaccifolium is a perennial herb up to 200 cm (79 in) tall. The lance-shaped or pointed oval leaves are 10 to 20 centimeters long and borne on petioles. The leaves have large stipules which form reddish ochrea up to 3 centimetres (1.2 inches) long. The inflorescence is a long array of branching cluster of many white or greenish flowers. Each flower is about 4 millimetres (0.16 inches) wide and has tiny protruding stamens tipped with yellow or pink anthers.