Redroot pigweed is one of the most familiar weeds of American gardens, fields, and roadsides, named for its pink to reddish taproot. Its exact homeland is uncertain, possibly eastern North America or Central America, but it now grows as a weed on nearly every continent. Its young leaves and seeds have long been eaten, including by Native American peoples of the West.
Appearance
- Appearance
- An upright annual 8 in–5 ft (0.2–1.5 m) tall, though mowed plants stay low and sprawl. Stems are green to red or striped, with dense hairs on the upper parts. The taproot is pink to red.
- Leaves
- Alternate, egg- to diamond-shaped leaves mostly 1.5–4 in (4–10 cm) long, up to about 6 in (15 cm) on big plants, with smooth, often wavy edges and hairs along the veins underneath.
- Flowers
- Tiny green flowers packed into thick, short, bristly spikes at the branch tips and leaf bases. Spiny-tipped make the spikes feel prickly.
- Flowering time
- July–September (Minnesota)
- Fruit
- A tiny capsule under 1/16 in (2 mm) that splits open around the middle to release one shiny black seed about 1 mm across.
Look-alikes
| Upper stem | Flower spikes | Leaf stalk | |
|---|---|---|---|
| Redroot pigweed | Densely hairy | Short, thick, not stiff | Half to about as long as blade |
| Smooth pigweed | Hairless or sparsely hairy | Tepals pointed | — |
| Powell's amaranth | — | Long and stiff; tepals pointed | — |
| Palmer amaranth | Hairless or nearly so | Much longer and slender | Longer than blade |
Where it lives
- Typical habitats
- gardens
- farm fields
- roadsides
- vacant lots
- Range
- Found across North America and treated as a weed throughout most of its range. Its exact origin is uncertain, so it is regarded as native in some regions and introduced in others; for example, it isn't considered native in Minnesota.
- Preferred conditions
- Disturbed, moist to dry soil in full sun to part shade.
- Flowering
Flowers Jul–Sep
Flowers Jul–Sep
Life cycle
- Seed dispersal
- A single plant can make hundreds of thousands of seeds, which spread by wind, water, and animals and can survive in the soil for many years.
Cautions
- Cautions
- No amaranth is known to be poisonous to people, but the leaves contain oxalic acid and can build up nitrates in rich soil. Cattle and pigs that eat large amounts over several days can be sickened or killed.
Culture and stories
- Culture and stories
- "Pigweed" is said to come from the plant's habit of springing up where hogs were pastured.
- Several Native American groups in the western US used it for food and medicine, and in Mexico its greens are sold as quelite quintonil.
- The seeds can be toasted or ground into flour, much like grain amaranth.
More species to explore
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