Lepidium

Lepidium is a genus of flowering plants in the family Brassicaceae, commonly known as peppergrass or pepperweed. The genus comprises several hundred species, distributed across temperate and subtropical regions of the world. Members range from small annual herbs to perennial plants that can form rosettes or upright stems, typically inhabiting disturbed ground, fields, roadsides, and coastal areas.

Lepidium species are usually herbaceous, with simple to lobed leaves and small white to pale yellow flowers arranged in slender racemes or spikes. The fruit is a flattened silique or, less commonly, a short silicle. Many species are annuals or biennials, producing seed in a single season; some are perennials and may persist for multiple years.

economically important species include Lepidium sativum, the garden cress cultivated for its peppery leaves and seed; Lepidium meyenii (maca), a cultivated root crop from the Andes; and several wild or weedy species such as Lepidium virginicum (Virginia pepperweed), Lepidium campestre (field pepperweed), Lepidium latifolium (broad-leaved pepperweed), and Lepidium perfoliatum (perfoliate pepperweed). Some of these, notably L. latifolium and L. perfoliatum, are considered invasive in parts of North America, where they can form dense stands and displace native vegetation.

Lepidium species are used in salads and garnishes in the case of garden cress, and in traditional contexts for some regional crops. They are also of interest to researchers studying Brassicaceae phylogeny and invasive plant dynamics.