The genus Mucuna, a member of the legume family of plants, contains six species of climbing vines called lianas that wind their way through the branches of trees in tropical rain forests. Buoyant Mucuna seeds drop from the vines and fall into creeks, streams and rivers and eventually float to the sea, where they are called sea beans. An extract of mucuna seeds contain a compound found useful in the treatment of Parkinson's Disease.
The mucuna plant produces rope-like clusters of blossoms. The blossoms, about 2 inches long, open only at night and when they are ready to be pollinated. Their color ranges from whitish-green to red, depending on the species.
Night-flying bats that thrive on blossom nectar bounce signals off objects in order to navigate. The blossom of the macuna plant contains a concave petal that acts as an acoustical mirror. When the bat emits its navigational sound, the mucuna petal bounces it back, guiding the bat to the nectar.
The pollinated mucuna flowers develop pods, typical of plants in the legume family. The pods hang from ropelike stems and each contains from two to six seeds; they are covered with tiny, velvety hairs that can be irritating if they are handled and especially painful if they get into the eyes.
The brown-to-black mucuna seeds have a thick, woody coat and contain cavities that make them float. They can drift in ocean currents for months or years after they are carried out of rain forest streams and creeks. The hard, marble-like seeds are often gathered and made into bead necklaces and bracelets.
Black Kwao Krua (M. collettii) produces black sap. The Thais use extracts of this species for medicinal purposes.
Cowhage (M. pruriens) produces long racemes of white to dark purple flowers and red seedpods. It is rich in L-dopa and the Indians have long used it as an aphrodisiac and to treat depression and nervous disorders.
The seeds of M. urens, which grows in Central America, wash up on beaches throughout the Caribbean.
M. sloanei is native to the Monteverde Cloud Forests of Costa Rica. Seeds of M. sloanei often wash up on beaches of the southern U.S.
The Guina creeper (M. bennettii) produces bright red flowers in the shape of a pea.
M. gigantean grows in the rain forests on the island of Maui in Hawaii. The seeds from this species are turned into necklaces sold to tourists in Waikiki.
Mucuna pods and seeds are rich in L-dopa (L-dihydroxyphenylalanine) a bitter, potentially toxic amino acid that is an intermediate compound in the formation of dopamine, a neurotransmitter in the brain. Dr. Bala V. Manyami conducted research at Texas A & M University in 1997 concluding that L-dopa contained in the powder of ground mucuna seeds was two to three times more effective than the same amount of synthetic L-dopa. Studies noted by the U.S. Department of Agriculture suggest that mucuna as a natural source of L-dopa might be more effective than artificial preparations for the treatment of Parkinson's Disease.