TALL WATERHEMP, Amaranthus
tuberculatus (Moq.) Sauer. 1, top of plant in flower; 2,
seed in the hull and dehulled. Annual, reproducing by seed. Stem
smooth, erect, ascending or somewhat prostrate, stout or slender, 3 feet
(0.9 m) up to 8 feet (2.4 m) tall. Leaves narrowly ovate to lanceolate,
long-petioled, alternate, 3 to 6 inches (7.6 to 15 cm) long. Flowers
small, greenish, surrounded by small bracts, in loose terminal and axillary
spikes; male and female flowers borne on separate plants. Seeds
oval, reddish-black, each contained in a bladderlike hull. Found
chiefly in cultivated crops or waste areas, especially on low ground. Other
very similar species, Amaranthus tamariscinus (Nutt.) Wood
and Amaranthus arenicola 1. M. Johnston, also occur in the
region. Some waterhemp in the region is probably a hybrid complex among
these various species.