A flowering pepperwort plant (Lepidium species) with a cup fungus, two silverfish, a fish larva and wood beetle. Colored etching by John Pass, c. 1813. 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, and pepperwort.