Common: Redroot Amaranth
Tropical America and introduced throughout the United States
This weed is an annual species that reproduces by seed and may establish itself aggressively in cultivated fields. It can get to be six feet tall with bristly looking greenish flowers clustered along the sides and top of the plant during late summer and autumn. This pigweed gets one of its common names from the reddish color at the upper portion of the taproot. However, there are many species of amaranth, and they cross-react allergenically.