Smooth Pigweed, Amaranthus hybridus
Family: Amaranthaceae; Pigweed Family
Vegetative Characteristics:
Seedling: hypocotyls red to green, usually glabrous; cotyledons green, glabrous
Stems: erect, 0.5-2.5 m tall, usually branched, stout; glabrous or sparsely pubescent apically
Leaves: alternate, 2.0-15.0 cm long, 1.0-6.0 cm wide, simple, ovate, glabrous, long-petioled
Reproductive Characteristics:
Inflorescences: monoecious, terminal panicles of numerous slender, cylindrical spikes about 1.0 cm thick and up to 15.0 cm long; bracts 2.0-4.0 mm long, equal to or longer than sepals, not stiff; female sepals 5, 1.0-2.5 mm long, straight, with acute tips
Fruits: utricle, obovoid or elongate-ovoid, 1.5-2.0 mm long, circumscissile dehiscent, wrinkled and rough when dry, numerous per spike
Seeds: lenticular, 1.0 mm diameter, dark brown
Special Identifying Characteristics:
⇒ erect summer annual; inflorescences in spikes, 1.0 cm or less thick; bracts short; plants monoecious
