about 175-220, see text
Lepidium is a genus of plants in the mustard/cabbage family, Brassicaceae. The genus is widely distributed in the Americas, Africa, Asia, Europe, and Australia. It includes familiar species such as garden cress, maca, and dittander. General common names include peppercress, peppergrass, pepperweed, and pepperwort. Some species form tumbleweeds. The genus name Lepidium is a Greek word meaning 'small scale', which is thought to be derived from a folk medicine usage of the plant to treat leprosy, which cause small scales on the skin. Another meaning is related to the small scale-like fruit.
There are about 175 to 220 species in the genus. 10 species are found in California.