Scientific Name: Amaranthus blitoides

Common Name: mat amaranth

Other Common Names: prostrate pigweed

Synonyms: Amaranthus graecizans

Habit: Prostrate pigweed tends to spread in multiple directions from the taproot system. They develop a mat across the soil. Prostrate pigweed spreads only by seeds.

Leaves: Leaves are alternate in arrangement, oval and approximately 1/2 inch in length. They are wider at the tip than at the petiole.

Identifying Characteristics: The stems of prostrate pigweed may be light green to reddish purple and are smooth. The first leaves of the plant are wider at the apex, and are slightly magenta on the underside.

Flower Seed Head: Flowers of prostrate pigweed are monoecious and appear from June through August. The flowers are small and green and appear on leaf axils.

Seed Fruit: The seeds of prostrate pigweed are glossy and black. They are rounded in shape and convex on the sides. They are approximately 1.5 mm in diameter.

Where Found: Prostrate pigweed is found throughout North America, in almost every state. It is most commonly found in disturbed or cultivated soil and is most excessive in the western United States

  • Life cycle: summer annual

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Amaranthaceae

  • Leaf arrangement: alternate

  • Leaf shape: lance

  • Leaf margin: entire

  • Flower color: green

  • Growth habit: prostrate and nonwoody

  • Leaf structure: simple

  • Flower diameter: nickle

  • Root structure: taproot

  • Leaf stalk: shorter than leaf