cow-itch

Mucuna pruriens is a climbing herb with stems that are either glabrous or sparsely covered with spreading yellowish hairs. The leaves are trifoliolate, with a central terminal leaflet that is rhombic-ovate and lateral leaflets that are oblique. The leaf surfaces are dark green on the upper side and grey-green on the underside, with dense white hairs. The inflorescence is an axillary or cauline pseudoraceme, bearing 2–3 flowers per node. The calyx is bilabiate and covered with irritant bristles and grey hairs. The plant flowers from September to the following January and fruits from October to the following April. The pods are covered with irritating hairs and are either straight or slightly curved, distinguishing the variety hirsuta from the typical variety pruriens.

Mucuna pruriens is typically found in tropical and subtropical regions, often in disturbed areas, along riverbanks, in secondary forests, and in open woodlands. It thrives in warm, humid climates and is commonly naturalized in regions with high rainfall. The species is widely distributed across South America, Central America, the Caribbean, Africa, and parts of Asia, including China, where it has been documented in multiple provinces.

Mucuna pruriens is cultivated for various purposes, including as a cover crop, green manure, and forage. It is valued for its nitrogen-fixing properties, which enhance soil fertility. The plant is also grown for its seeds, which are used in traditional and modern medicine. Cultivation is typically done in tropical and subtropical climates where the plant can thrive with adequate moisture and warmth. It can be propagated through seeds and requires well-drained soil for optimal growth.

Mucuna pruriens has a range of traditional and modern uses. The seeds are used in Ayurvedic and Chinese medicine to treat neurological and hormonal conditions, including Parkinson's disease, due to their high L-dopa content. The plant is also used as a green manure and cover crop to improve soil fertility and suppress weeds. The hairy pods are sometimes used for industrial purposes, and the plant is also cultivated for ornamental use in some regions. However, the irritant hairs on the pods and leaves can cause skin rashes and should be handled with care.