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Canadian Clearweed (Pilea pumila (L.) A. Gray)

Also known as Canadian clear weed.

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Canadian Clearweed


An annual related to nettles, but lacking stinging hairs. Named for its translucent stems.

Range - Expand

Native or Not Present

This tentative map is based on our own research. It may have limited data on Canada and/or Mexico, and there is some subjectivity in our assignment of plants as introduced vs. expanded. Read more in this blog post.


Grows in moist to wet areas in light shade, and rich, loamy soil. Usually requires some exposure of soil to germinate. Established plants are able to survive temporary flooding, but not standing water.

Mostly found in forests, especially floodplain forests but also poorly drained sites in upland forests.

Also thrives in wet, poorly-drained areas of shady yards and gardens.

Life Cycle

This species is a strict summer annual. Seeds sprout in spring, where they often blanket areas of exposed soil. Only a small portion of these plants will reach maturity.

Flowers are inconspicuous and wind-pollinated. The plant dies after producing seeds. Usually found in large patches or colonies where conditions favor it.

Populations ebb and flow with changing weather patterns from year to year, affected by moisture levels.


This species is initially hindered by the allelopathy of garlic mustard (Alliaria petiolata), which commonly occurs in the same habitats, but it is able to adapt to the presence of garlic mustard after several generations.

Pilea pumila (Clearweed) | Illinois Wildflowers (About This Site)

Pilea pumila (Canadian Clearweed) | USDA PLANTS Database (About This Site)

Pilea pumila | Go Botany (About This Site)

Canada Clearweed | iNaturalist (About This Site)

Pilea pumila | Biota of North America Project (BONAP) (About This Site)

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Photo © , CC BY-SA 4.0.
Photo © , CC BY-SA 4.0.