Scientific Name: Amaranthus palmeri

Common Name: Palmer amaranth

Other Common Names: carelessweed

Habit: This erect summer annual can be found flowering from June through October. Germination occurs from April through September.

Leaves: The alternately arranged leaves are lance to egg shaped and occur on long petioles. The leaves can be from 2 to 8 inches in length and 1/2 to 2 1/2 inches in length. The undersides of the leaves have prominent white veins. There is one central stem from which many side branches will arise. The central stem can reach 6 1/2 feet in height.

Identifying Characteristics: This plant can be distinguished from other pigweeds by its long narrow terminal spike. Another identifying feature is the lack of hair on the leaves.

Flower Seed Head: The small green flowers occur on a terminal spike up to 1 1/2 feet in length. Smaller spikes of flowers can be found on the stem above some leaf petioles. The male and female flowers are found on different plants.

Seed Fruit: The seeds develop in a utricle that can grow up to 2 mm in length. Each utricle contains one glossy black seed.

Where Found: This plant can be found infesting croplands.

  • Life cycle: summer annual

  • Milky sap: Not Present

  • Plant type: Herb

  • Thorns: Present

  • Plant family: Amaranthaceae

  • Leaf arrangement: alternate

  • Leaf shape: oval

  • Ochrea: Not Present

  • Leaf margin: entire

  • Stem hairs: no hairs

  • Flower color: green

  • Growth habit: upright and nonwoody

  • Stem: round or oval

  • Leaf structure: simple

  • Leaf hairs: no hairs

  • Flower diameter: pencil

  • Flower symmetry: not symmetrical

  • Root structure: taproot

  • Leaf stalk: longer than leaf