Psorothamnus
Psorothamnus is a genus of plants in the legume family. These are shrubs and small trees. Many are known by the general common name indigo bush. Some are referred to as daleas, as this genus was once included in genus Dalea. These are generally thorny, thickly branched, strongly scented bushes. Most species bear lupinlike raceme inflorescences of bright purple legume flowers and gland-rich pods. Psorothamnus species are native to the southwestern United States and northern Mexico.
The genus formerly included additional species, but was found to be paraphyletic, and genus Psorodendron was reinstated to accommodate sections Xylodalea, Capnodendron, and Winnemucca.
Species
Four species are currently accepted.Psorothamnus emoryi Rydb. – dyebush, Emory's indigo bushPsorothamnus polydenius Rydb. – Nevada daleaPsorothamnus scoparius Rydb. – broom daleaPsorothamnus thompsoniae S.L. Welsh & N.D. Atwood – Thompson's daleaFormerly placed here
- Psorodendron arborescens, as Psorothamnus arborescens Barneby
- Psorodendron fremontii, as Psorothamnus fremontii Barneby
- Psorodendron kingii, as Psorothamnus kingii Barneby
- Psorodendron schottii, as Psorothamnus schottii Barneby
- Psorodendron spinosum, as Psorothamnus spinosus Barneby