The rhizome and rootlets of Cypripedium pubescens, and of Cypripedium parviflorum.

Characters. - Horizontal, bent, four inches (10 centimetres), or less, long; about one-eighth of an inch (3 millimetres) thick; on the upper side beset with numerous circular cup-shaped scars; closely covered below with simple, wiry rootlets varying from four to twenty inches (10 to 50 centimetres) in length; brittle, dark brown or orange-brown; fracture short, white; odour faint but heavy; taste sweetish, bitter and somewhat pungent.

Use. - It has an antispasmodic action similar to that of valerian, but it is less powerful.

Scitamnaceae.