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Manitoba Museum

Spiderwort (Commelinaceae)

Western Spiderwort

Tradescantia occidentalis (Britt.) Smyth

The only member of its family native to Western Canada, Western Spiderwort is a federally protected species. The broken stems secrete a sticky substance, which forms cobweb-like strands when hardened, giving the plant its common name. It has fleshy roots that may have been used by Indigenous groups as a cooked vegetable. High spring moisture benefits the annual population size. However, the main factors in population decline are habitat loss and sand dune stabilization.

Flower Colour:

  • Blue

Flowering Season:

  • Summer

Flowering Months:

  • July
  • June

Canadian Rarity Status:

Protected under Canada’s Species at Risk Act, Manitoba’s Endangered Species Act and Saskatchewan’s provincial Wildlife Act. Plants may be covered under Alberta’s Wildlife Act, though no status has yet been assigned to the Western spiderwort. The collection of wild plants and seeds is illegal on public lands.

Physical Appearance:

Western Spiderwort is an herbaceous perennial with a thin stem up to 60 cm tall. It has long, grass-like alternate leaves with purplish veins. The flowers consist of three rounded petals that are usually blue, but sometimes white or pink. Clusters of up to 25 flowers occur at the top of the stem. One to two flowers open each day and last only a few hours.

Gardening Notes:

Do not purchase wild-collected seeds or plants. Seeds and/or plants from nursery-raised stock may be available.

Canadian Distribution:

  • Alberta
  • Manitoba
  • Saskatchewan

Prairie Types:

  • Mixed Grass Prairie


  • Prairies
  • Sand dunes

Moisture Conditions:

  • Dry

Light Preference:

  • Full Sun

Soil Preference:

  • Sand
Western Spiderwort