E-Flora BC: Electronic Atlas of the Flora of British Columbia

Amaranthus retroflexus L.
rough pigweed (redroot amaranth)
Amaranthaceae (Amaranth family)

Introduction to Vascular Plants

© Bryan Kelly-McArthur  Email the photographer   (Photo ID #85743)

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Distribution of Amaranthus retroflexus
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Species Information

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Annual herb; stems 50-100 cm tall, simple to freely branched, long-hairy with dandruff-like scales below the flowers.
Alternate or opposite, leaf blades 3-8 cm long, hairy below, at least along the veins, narrowed abruptly to the stalks.
Inflorescence in terminal and axillary spikes; bracts long and needle-shaped or spiny; stamens usually 5, sometimes 4.
Capsules opening along an "equator", the top coming off like a lid, 1-seeded; seeds 1 mm long, rounded and convex.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Moist to dry fields, disturbed areas and waste places in the lowland, steppe and montane zones; frequent in S BC, rare northward; throughout N. America and the Old World.

Source: The Illustrated Flora of British Columbia


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Amaranthus retroflexus var. salicifolius I.M. Johnst.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References