Shampoo ginger

Shampoo ginger (Zingiber zerumbet) is a perennial herb of the ginger family (Zingiberaceae), 0.6–2 m tall, growing in clumps from a branching, strongly aromatic rhizome. The leaves are alternate, lanceolate, 20–40 cm long, with sheaths clasping the pseudostem. Its most distinctive feature is the cone- or ball-shaped inflorescence rising from the base, made of overlapping bracts; the bracts are green when young and turn bright red as they age, and a clear, fragrant mucilaginous juice oozes from between them. The true flowers are small and pale yellow, nestled among the bracts. The rhizome is swollen, pale-yellow inside, hot, spicy and aromatic, and holds an essential oil rich in zerumbone.

Shampoo ginger is native to Southeast Asia and the Malay Archipelago and is widely grown across the humid tropics of Asia, Oceania and the Americas. In Vietnam it grows wild and is planted in gardens. The English name "shampoo ginger" comes from the use of the mucilage in the inflorescence as a hair wash and scalp tonic that also eases headache. In traditional medicine the rhizome is pungent and warming, used to warm the middle, dispel cold and treat stomach ache, diarrhoea, fever and joint pain. Modern research shows that zerumbone in the rhizome is anti-inflammatory and antibacterial and is of interest in cancer research.