Amaranthus retroflexus L.
Family: Amaranthaceae
redroot amaranth, common amaranth, pigweed, rough amaranth, rough pigweed, wild-beet amaranth
Amaranthus retroflexus image
Paul Drobot  
Etymology: Amaranthus: from the Greek amarantos for "unfading," referring to the long-lasting flowers
Plants: annual, up to 6' tall forb, freely branched forb hairless except in the inflorescence; stems with no spines and often with a reddish base
Leaves: alternate, ovate, underside smooth with whitish veins, stalk equal to or longer than the blade
Flowers: green, tiny, 3-5-parted; inflorescence dense, stiff, terminal, spike-like cluster usually unbranched or with a few, erect, widely-spaced branches
Habitat: disturbed sites