The orchid family (Orchidaceae) is the second largest family of flowering plants, with about 880 genera and some 26,000 species distributed nearly worldwide. Orchids are perennial herbs and feature unusual bilaterally symmetric flowers, with masses of pollen known as pollinia, and tiny, dustlike seeds. Many are grown as ornamentals for their showy flowers, and several are of economic importance as the source of the flavouring vanilla. The following is a list of some of the major genera and species in the family Orchidaceae, arranged alphabetically by common name or genus.