Buck-bean, Bog-bean, or Marsh Trefoil (Menyanthes trifoliata), a beautiful British plant, occurring also from Siberia and N.W. India into North America, the only species of a genus of the gentian family. It has a creeping, starchy, perennial rhizome; fleshy ternate leaves something like the leaflets of the broad-bean; a racemose scape of pentamerous flowers with petals delicately fringed, pink outside and white within; and a one-chambered capsule bursting into two valves. It grows in wet bogs or pools, reaching an altitude of 1,800 ft. in the Lake district. In Lapland the rhizome is used as a bread-stuff in times of scarcity; and as the plant shares the bitter tonic properties of the rest of the family, its leaves are used in Silesia as a substitute for hops, as they were formerly in Sweden, whilst they once had a reputation as a febrifuge and a remedy for gout and rheumatism.