Orchids are among the most highly prized of ornamental plants. In Mexico the flowers are used symbolically by the natives; each one conveys a sentiment associated with different ceremonies or religious figures. From the time that orchids were first imported from the Bahamas to Britain (in the early 18th cent.) these flowers have been cultivated for their commercial value and have been successfully hybridized and variegated. Many orchids are now propagated by tissue culture methods. Hawaii has become a major center for commercial orchid culture. A species of the Vanilla genus of tropical America is important economically as the source of natural vanilla flavoring.