Psoralea is a genus in the legume family (Fabaceae). Although most species are poisonous, the starchy roots of P. esculenta (breadroot, tipsin, or prairie turnip) and P. hypogaea are edible. A few species form tumbleweeds. Common names include tumble-weed (P lanceolata), and white tumbleweed. Psoralea aculeata Psoralea adscendens Psoralea affinis ... Found on http://en.wikipedia.org/wiki/Psoralea
Psoralea is a genus of shrubby and herbaceous plants belonging to the family Leguminosae. They usually have compound leaves and heads of racemes or spikes of blue, red or white flowers. Found on http://www.probertencyclopaedia.com/browse/BPA.HTM