Amaranthus retroflexus L.

  • Authority

    Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

  • Family


  • Scientific Name

    Amaranthus retroflexus L.

  • Description

    Species Description - Monoecious; stem stout, erect, usually branched, to 2 m; plant scurfy-villous in and for some distance below the infl; lvs long-petioled, ovate or rhombic-ovate, usually hairy beneath at least along the veins, to 10( 15) cm in well developed plants; principal infl a terminal panicle of several or many short, densely crowded, obtuse spike-like thyrses, the whole 5–20 cm; similar but smaller panicles produced from the upper axils; bracts rigid, subulate, 4–8 mm, much surpassing the cal; sep 5, those of the pistillate fls oblong-lanceolate, slightly outcurved above, rounded or truncate or emarginate at the tip, and often minutely mucronate, with simple midvein, at maturity 3–4 mm and much-surpassing the fr; stamens 5; style-branches fairly long, erect or slightly recurved; fr compressed, 1.5–2 mm, circumscissile at the middle, the upper part rugulose; seed round-obovate, 1–1.2 mm; 2n=34. Native of tropical Amer., now a common weed throughout most of the U.S. and also in the Old World.

  • Common Names

    redroot, rough pigweed