Redroot pigweed is an abundant seed producer that may be found throughout the United States in horticultural, nursery, and agronomic crops, landscapes, roadsides, and also in pastures and forages. Lower surfaces of cotyledons have a reddish tint. Hairs may occur on the leaf margins and along veins, especially along the lower leaf surfaces.
Leaves have wavy margins and hairs that occur along the veins of the lower leaf surfaces.
Stems usually have short hairs, especially near the upper portions of the plant. A shallow taproot that is often, but not always, reddish in color. A single seeded utricle that reach 2 mm in length and are wrinkled when dry. Each utricle splits open in the middle to expose a single glossy black to dark brown seed that is 1 to 1.2 mm long and ovate in outline. Each terminal panicle contains many densely packed branched spikes that have bracts that are 4 to 8 mm long and 2-3 times longer than the sepals.