Short-lived, mostly annual, 1-6 dm, evidently hirsute and tending to be a little viscid; lvs numerous, cauline, opposite, linear or nearly so, entire, 2-8 cm נ1-3 mm; peduncles axillary, 2-8 cm; spikes 0.5-1.5 cm, dense, nearly 1 cm thick; bracts broad, rounded, conspicuously scarious-margined; the lowermost abruptly and firmly foliaceous-caudate; cor-lobes 1.5-2 mm, soon reflexed; seeds 1 or 2, brown, 2-3 mm; 2n=12. A weed in waste places, especially along railroad tracks; native to the e. Mediterranean region, now well established in e. U.S. (P. indica; P. arenaria) The name has often been misapplied to a related sp. without caudate tips on the bracts.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.