Golden bean (Thermopsis rhombifolia)

Golden bean (Thermopsis rhombifolia)
Also known as: Richards buffalo bean, prairie bean, golden banner, buffalo bean, prairie pea


Bloom time: May – June

Additional photos:

General: A wildflower (or herb), 15 cm to 50 cm tall, usually growing in large patches. The fat stalk is covered with downy hairs when it emerges from the ground. Soon the stalk straightens to a spike of golden flowers.

Leaves & Twigs: Leaves are dark green with 3 leaflets, each rounded leaflet 2 cm to 3 cm long.

Flowers & Fruits:

  • Flowers are bright yellow, each 12 mm across, and together form a dense cluster. They resemble the flowers of a pea.
  • A grayish-brown, hairy, curved pod, about 5 cm long with 4 to 6 seeds.

Habitat: Golden bean plants can be found in open sandy areas in prairie and aspen forest where the water table is high.

PlantWatch Pointers: If the plants are very abundant, mark a plot about one metre by one metre in size to observe.

To Observe:

  • First bloom: When the first flowers are open in the patch observed.
  • Mid bloom: When approximately half (50%) of the flowers on the plants under observation are now open. The other 50% are still unopened buds.

Distribution Map:

Distribution Map

This species is monitored in:

  • Alberta

First nations peoples’ used the flowering time of Golden bean or “Buffalo bean” to indicate that it was time for the spring hunt of buffalo bulls.