Stems slender, weak, annual, decumbent, or climbing over other plants by the numerous sharp, recurved prickles which arm its four prominent angles. Leaves lanceolate-sagittate or oblong-sagittate, 1 to 3 inches long, pointed at the apex, slightly rough margined, the lower leaves petioled, upper ones sessile or nearly so, prickly on the petioles and beneath on the midribs; ocreae oblique, not ciliate. Flowers in terminal heads or racemes, rose-colored or greenish; stamens usually eight in number; style three-parted.

In wet soil, Newfoundland and Nova Scotia to the Northwest Territory, south to Florida and Kansas. Flowering from July to September.

Memoir 15 N. Y. State Museum

Plate 48

Halberd Leaved Tearthumb

Halberd-Leaved Tearthumb - Tracaulon arifolium