prostrate pigweed

plant

Also known as: Amaranthus graecizans, mat amaranth

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 23, 2026

Quick Summary

Prostrate pigweed, scientifically known as Amaranthus blitoides, is an annual plant native to western North America. It is characterized by its prostrate or decumbent growth habit, meaning it lies flat or has stems that rise at the tips. This plant typically has alternate, simple, spatulate leaves and small greenish flowers clustered in the leaf axils. Prostrate pigweed has become established as a weed in various locations, particularly in neglected fields and waste areas. It is one species within the broader category of pigweeds, which are weedy annual plants belonging to the amaranth family (Amaranthaceae).12

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

pigweed
Prostrate pigweed, or mat amaranth (A. graecizans), grows along the ground surface with stems rising at the tips; spiny pigweed, or spiny amaranth (A. spinosus), has spines at the base of the leafstalks; and rough pigweed, or redroot (A. retroflexus), is a stout plant up…
Read More
Prostrate pigweed, or mat amaranth (A. graecizans), grows along the ground surface with stems rising at the tips; spiny pigweed, or spiny amaranth (A. spinosus), has spines at the base of the leafstalks; and rough pigweed, or redroot (A. retroflexus), is a stout plant up…
Read More