Waterhemp, Amaranthus tuberculatus
Family: Amaranthaceae; Pigweed Family
Vegetative Characteristics:
Seedling: hypocotyl green to red, glabrous to lightly pubescent; cotyledons green to reddish, glabrous
Stems: erect, occasionally ascending; 0.7-3.0 m tall, slender, green or red (females usually red), glabrous or sparsely pubescent
Leaves: alternate 1.0-15.0 cm long, 0.5-3.0 cm wide, simple, narrowly ovate to lanceolate, glabrous, long-petioled
Reproductive Characteristics:
Inflorescences: male and female flowers on sperate plants (dioecious); terminal spike, simple to highly branched, bracts 1.0-1.5 mm long, slender midrib extending beyond lamina; carpellate sepals completely lacking or rudimentary; staminate sepals 5, nearly equal, 2.5-3.0 mm long, greenish
Fruits: utricle, obovoid or subglobose, 1.5-2.0 mm long, dehiscing irregularly, smooth or tuberculate
Seeds: lenticular, 0.8-1.0 mm diameter, lustrous, dark reddish to black
Special Identifying Characteristics:
⇒ erect summer annual; dioecious; utricles dehiscing irregularly
