Amaranthus caudatus L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Cult. ornamental and grain-amaranth, apparently derived from the S. Amer. A. quitensis Kunth; monoecious, stout, erect, to 2 m; lvs long-petioled, elliptic to rhombic-ovate, to 2 dm; infl large and showy, generally bright red in life, composed of several to many drooping, spike-like thyrses, the terminal one 1–3 dm, much longer than the lateral; bract of the pistillate fls with slender midrib, not surpassing the fr; sep 5, outcurved above, the inner spatulate and obtuse or emarginate, all over 2 mm and nearly equaling the fr; style-branches slender, spreading from the base; seed most commonly pale ivory, and when fresh flushed with red around the rim, less commonly dark brown; 2n=32, 34. Amer. cultigen, originally cult. for grain, now relictual as a grain-plant, but widely cult. as an ornamental, occasionally escaping or persistent, but scarcely established in our range.