Fibrous-rooted perennial from a short, stout, erect caudex, glabrous or rather inconspicuously hairy, especially below; lvs with broadly elliptic to broadly ovate or cordate- ovate blade ±abruptly contracted to the well defined petiole, the blade entire or irregularly toothed, mostly 4-18 נ1.5-11 cm, 1.3-2(-3) times as long as wide, strongly 3-several-nerved, the nerves diverging at the base of the blade, ±parallel to the margin; petiole only seldom anthocyanic at base; scapes 5-25 cm; spikes dense but narrow, less than 1 cm thick, commonly 5-30 cm long, essentially glabrous; bracts broad, ovate- obtuse, mostly 2-4 mm, with a prominent, acute keel and thin margins; sep ovate, obtuse, the rounded keel about as wide as the scarious margins; cor-lobes ca 1 mm or less, reflexed after anthesis; stamens 4, exsert; fr rhombic-ovoid, 2.5-4 mm, circumscissile near or a little below the middle; seeds 6-30, 1 mm, strongly reticulate; 2n=12, 24. Native of Eurasia and probably also parts of N. Amer., naturalized throughout the U.S. and s. Can. in lawns, roadsides, and waste places. (P. asiatica)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.