Northern Prairie Wildlife Research Center
Redroot Amaranth (Amaranthus retroflexus)
- Family: Pigweed (Amaranthaceae)
- Flowering: July-October.
- Field Marks: All amaranths have obscure, crowded, green flowers. The green amaranth differs from all others by lacking spines, by having both male and female flowers on the same plant, by having spikes much longer than broad, and by having sepals of the female flowers not pointed at the tip and about 1/5 inch long.
- Habitat: Cultivated fields, roadsides, disturbed areas.
- Habit: Coarse annual with fibrous roots.
- Stems: Erect, often branched, hairy, green or sometimes reddish near the base, up to 6 feet tall.
- Leaves: Alternate, simple, elliptic to ovate, usually somewhat toothed, hairy, pointed at the tip, tapering to the base, up to 4 inches long.
- Flowers: Borne in short, dense, sometimes branched spikes up to 8 inches long, green, each flower unisexual but with both the male and female flowers on the same plant, with bracts about 1/3 inch long, longer than the sepals.
- Male Flowers: Sepals 5, green, about 1/6 inch long; petals 0; stamens 5.
- Female Flowers: Sepals 5, green, about 1/5 inch long, not pointed at the tip; petals 0; ovary superior.
- Fruits: 1-seeded, dry, smooth, 1/6 inch long, the seeds dark red-brown.
- Notes: This aggressive weed is native to tropical America, but is found throughout the United States in disturbed areas. Young plants can be cooked and eaten as a vegetable. Seeds can be made into bread. Pigs are particularly fond of this species as a food. There are reports of this plant when growing in fertilizer-rich soils as being harmful to livestock. This species may cause hay fever in certain individuals.
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