composite image of key traits

Powell Amaranth

Grows 3 to 6 feet tall and populations resistant to two herbicide groups have been found outside the Northeast and Mid-Atlantic regions.

Powell Amaranth

Amaranthus powellii

Leaves: Diamond-shaped, maybe darker green with smooth leaf margins and v- shaped variegation present. Leaf petioles are shorter or no longer than the leaf blade. 

Stems: Green, red, or striped and sparsely hairy to smooth. 

Height: 3-6 feet tall. 

Flowers: Male and female flowers are produced on the same plant (monoecious). Inflorescences consist of terminal flower heads with fewer branches and spiny bracts. May be confused with Palmer amaranth; distinguished by petiole length, presence of male and female flowers on the same plant, as opposed to separate plants. 

Herbicide resistances in US: WSSA Groups 2, 5. 

Herbicide resistances in Mid Atlantic and New England: None Reported.

Resistance information updated April 2025.

Powell amaranth leaves
Powell amaranth leaves
Powell amaranth leaf
Powell amaranth leaf

Images above: Powell amaranth leaves are diamond-shaped and may be darker green than other species. Leaf petioles are shorter or no longer than the leaf.

powell amaranth stem
Powell amaranth stems are minimally hairy, compared to other Amaranthus species.
Powell amaranth stem
Powell amaranth stems are minimally hairy, compared to other Amaranthus species.

Images above: Powell amaranth stems are minimally hairy, compared to other Amaranthus species.

Powell amaranth flower heads
Powell amaranth flower heads are not highly branched and flowers have bracts.
Powell amaranth flower bracts.
Powell amaranth flower bracts.

Images above: Powell amaranth flower heads are not highly branched and the flowers have bracts (right)

powell amaranth cotyledons
Powell amaranth cotyledons
powell amaranth seedling
Powell amaranth seedling

Image above: Powell amaranth cotyledons (left) and seedling (right).

powell stem
powell plant

Images above: Powell amaranth stem (left) and plant (right).