Erect, taprooted annual to 7 dm, with the aspect of sect. Persicaria; stem beset with scattered short, stout, recurved prickles, otherwise largely glabrous except for the conspicuously stipitate-glandular branches of the infl; lvs lanceolate or narrowly elliptic, 5-15 נ1-2.5 cm, tapering to the short petiole, rough-strigose along the midrib and main veins at least beneath, otherwise largely glabrous; ocrea coarsely antrorse-strigose, but with few or no cilia around the top; racemes lax, rather short; mature perianth 3.5-4 mm, constricted at the base; achenes plump, dark, dull, 2.5-3 mm long and wide. Native of e. Asia, locally intr. as a weed in Minn., and to be expected elsewhere.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.