Redroot Pigweed

Redroot Pigweed

Amaranthus retroflexus L.

Amaranthaceae (Pigweed Family)

▲ seedling

▲ ▼ young plants

▲ ▼ mature plants

▲ ▼ flowering plants

▲ ▼ flowering plants

▲ ▼ flowering plants

▲ ▼ inflorescences

▲ ▼ inflorescences

▲ ▼ inflorescences

▲ "reddish" root

Amaranthus retroflexus: (Bayer Code: AMARE; US Code AMRE)

  • Warm-season, aggressive annual weed with upright to branching growth habit
  • Stems & leaves have rough or hairy texture to them
  • Roots and stem bases tend to be pinkish or red
  • Leaves oval with prominent sunken veining
  • Terminal inflorescence is thick with sharp bracts sticking out
  • Common in all cultivated crops, disturbed sites, non-crop land
  • Can accumulate nitrates to toxic levels for grazing cattle
  • Produces up to 117,000 seeds/plant in a growing season
  • Seed can survive 40 years buried in soil
  • Can reduce yield of corn by 25-30% if only 1 plant per foot of row

(Updated January 15, 2019)

Go to Midwest Weeds and Wildflowers Home Page