This yellow-flowered legume can be found growing locally in open woodlands. It flowers May through June. It is a perennial herb, growing 2-3 feet high. Easy to cultivate, it is propagated in the spring by division of rootstocks or by seeds. The scientific name of the genus comes from the Greek thermos, a lupine, and opsis, an allusion to the resemblance to lupines. It belongs to the pea or bean family (Fabaceae).