Pigweed, redroot (Amaranthus retroflexus)

Pigweed, redroot description

Usually up to 5 ft in height, the erect stem has fine short hairs and is freely branched. The leaves are simple, alternate, dull green, with hairs on the veins on the underside. Well developed root system with shallow red roots.

Propagation

Annual. Small, dark, red to brown seed.

Similar species

Prostrate pigweed, smooth pigweed, and Powell amaranth. Smooth and redroot pigweed are difficult to distinguish until flowering stage.

Distribution

Widespread, but mostly a problem in the Great Plains.

Identifying Pigweed, redroot

Seedling

Seedling stems are red to green, smooth and hairless to slightly hairy. First leaves are green and hairy with indented tips and smooth edges.

Juvenile plant

Top leaves are rounded and fine small hairs can be found on the plant.

Mature plant

Stems erect, usually branched, 2 to 4 feet, sometimes much higher, at maturity. Bottom of branches thick and smooth. Upper branches and stem slightly to very hairy. Stems red to red striped.

Leaves alternate, ovate to lanceolate, smooth edges, dull green above and lighter below. Prominent white veins and slightly hairy underneath, long stalks. Shallow notch at tips of young plants.

Root structure description

Taproot, shallow, red or red striped.