What is "streptanthus"

Streptanthus is a genus within the mustard family, Brassicaceae. There are about 35 known species within the Streptanthus genus, distributed mostly throughout western North America. The common names for this genus are twistflower and jewelflower. Twenty-four of the species and eleven lesser taxa occur in California, thirty-two of which are California endemics; seventeen of these California taxa are classified as rare plants.