Amaranthus hybridus L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Monoecious, to 2 m, usually freely branched, scurfy- villous at least in the infl; lvs long-petioled, ovate or rhombic-ovate or lanceolate, mostly acutish, the larger ones on well developed plants often 15 cm or more; infl dull greenish or slightly reddish, not showy, terminal, lax, generally with many short, crowded lateral branches and often with nodding tip; bracts mostly 3–4 mm, slightly surpassing the sep and fr, with fairly thick, long-excurrent midrib; sep 5, those of the pistillate fls mostly 1.5–2 mm, about equaling the fr, with simple midvein, straight, acute; stamens 5; style-branches rather short, erect; fr rugose, circumscissile; seed dark brown, ca 1 mm; 2n=32. Originally native to tropical Amer., now a cosmopolitan weed.