overlay image

Manitoba Museum

Legume (Fabaceae)

Lance-leaved Psoralea

Psoraliadium lanceolatum (Pursh) Rydb.

This prairie perennial has white and purple pea-like flowers that are pollinated by visiting moths, including the rare Dusky Dune Moth. Plants can be found in the Mixed Grass prairies of Saskatchewan and Alberta where they grow on sandy soils and sand dunes. Their long rhizomes help them to colonize the unstable surfaces of dunes. Seeds of this species are eaten by the rare Ord’s Kangaroo Rat and can be found in their caches. Indigenous people have used these plants for medicinal purposes, and the roots are useful for making string.

Flower Colour:

  • White

Flowering Season:

  • Summer

Flowering Months:

  • July
  • June

Canadian Rarity Status:

Not rare.

Physical Appearance:

The semi-erect, hairy stems grow 10 to 50 cm tall, and are dotted with glands. Leaves are alternate and palmately divided into three linear to lance shaped leaflets, with hairy undersides and noticeable glands. Flowers are arranged in a dense spike. Each one has one upper banner petal, two wings and two smaller fused petals (keel) tipped with purple. Fruits are hairy, glandular, capsules.

Similar Species:

Breadroot (Pediomelum esculentum (Pursh) Rydb.), Silverleaf Psoralea

Gardening Notes:

Seeds and/or plants may be available from greenhouses and seed supply companies specializing in native plants.

Canadian Distribution:

  • Alberta
  • Saskatchewan

Prairie Types:

  • Mixed Grass Prairie


  • Prairies
  • Sand dunes
  • Sandstone Outcrops
  • Savannahs
  • Streambanks

Moisture Conditions:

  • Dry
  • Moderate

Light Preference:

  • Full Sun

Soil Preference:

  • Sand
Lance-leaved Psoralea