Lax annual to 4 dm; lvs 1-5 cm, often splashed with red, glabrous or often bristly-hirsute beneath, ovate or deltoid, truncate or abruptly contracted to the winged petiole, which tends to be expanded and clasping at base; ocreae often bristly below; peduncles often stipitate-glandular; infl capitate, the greenish-white bracts equaling or exceeding the 8-30 fls; perianth greenish-white or anthocyanic, 2 mm at anthesis, accrescent to 3 mm and strongly surpassing the achene; achenes lenticular, red-brown, reticulate-ridged, elliptic, 1.5-2 mm; 2n=48. Moist, shady places; native of Asia, sometimes grown as a ground cover, and occasionally escaped into relatively stable habitats in N.Y., Conn., and Pa.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.