Book excerpt: Native Orchids of Trinidad and Tobago provides detailed descriptions of the native species and varieties of orchids from Trinidad and Tobago. The Orchidaceae is the largest family of flowering plants with between 15,000 and 20,000 known species and varieties in from 500 to 600 genera; and new ones are being discovered by almost every botanical expedition to tropical areas. In Trinidad and Tobago, the Orchidaceae is the second largest family of flowering plants in terms of number of species. The native species and varieties known at the present time number 181, and they belong to sixty-six genera. The genera are enumerated in strict phylogenetic sequence, in accord with SCHLECHTER'S system. The species are listed alphabetically under the genera. An attempt has been made throughout to indicate synonymy as completely as possible even to the inclusion of binomials, which have never been used in connection with the flora of Trinidad and Tobago. The description of each genus has for the most part been drawn up to cover the morphological limits shown by the concept throughout its entire geographic range, whereas the specific descriptions are usually based only upon material collected in Trinidad and Tobago.