Asiatic Tearthumb

(Polygonum perfoliatum)

Asiatic Tearthumb (Polygonum perfoliatum  L.)

Alien: Native of Asia.

Identification: A reclining, almost vinelike plant. Flowers greenish, small, arranged in clusters with a large, round green bract at their bases. Fruit a round blue to purple-black berry. Leaves triangular. Leaf petioles and stems with recurved spines.Stems 3 to 9 feet in length.

Distribution: Currently found from Ohio to New York and south to Virginia and West Virginia. Also known from Oregon.

Habitat: Asiatic Tearthumb is found in wet, open areas such as forest bottom land and wet fields.

Flowering period: August to October.

Similar Species: The spiny stems, triangular leaves, and fruits are highly distinctive.

Comments: Asiatic Tearthumb is a pernicious weed and takes over open areas in the forest and forest edges, crowding out the native vegetation. The spiny stems and leaf petioles, as well as the tangled stems, make it nearly impossible to walk through.