Taisha is the author of today’s entry. She writes:
Thermopsis rhombifolia is also known as the buffalo bean, golden bean, or prairie thermopsis. This photo was taken by Michael McNaughton (aka michaelmcnaughton55@Flickr) who has recently started contributing to the Botany Photo of the Day Flickr Pool. Thanks for sharing with us, Michael!
A member of the pea family or Fabaceae, Thermopsis rhombifolia, is primarily distributed through the Canadian Prairies and the Central Great Plains of the United States. Habitat-wise, the species prefers xeric grasslands with alluvial soils. The slender stem with slightly zigzagged branches holds dark green leaves divided into three leaflets. The inflorescence, a raceme, bears bright yellow flowers which are either scattered or collected in whorls. Characteristic of much of the family, the fruit is a leguminous pod.
According to Native American Ethnobotany by Daniel E. Moerman, Thermopsis rhombifoia was/is used by the Cheyenne as an analgesic or cold remedy, by smoking the dried leaves. The Blackfoot used the yellow petals to colour their arrow shafts yellow. Also, the flowering time of the buffalo bean, suggestive of its common name, indicated to the Flathead and Blackfoot that it was prime buffalo hunting season and (for the Blackfoot people, at least) time to collect buffalo tongues in preparation for the Sun Dance.