The nomenclature of tribes and subtribes in the Orchidaceae is reviewed, and brought into line with the rules of botanical nomenclature. Tribal definition is discussed, and a different delineation of the Neottieae and Epidendreae is proposed. The Apostasieae are considered to be primitive orchids. The Vandeae are not considered to be clearly separable from the Epidendreae. A "phylogenetic" arrangement of recognized subtribes is proposed, and keys are given. A broader interpretation is given, especially of the subtribes Chloraeinae, Spiranthinae, Cyrtopodiinae, Epidendrinae, Maxillariinae and Oncidiinae. About 40 subtribes are recognized (as compared to 80 in Schlechter's system). The need for further revision is recognized. Evolutionary patterns are discussed for several features of the orchid plant, and the phylogeny of the family briefly considered. ROBERT L. DRESSLER, Missouri Botanical Garden, 2315 Tower Grove Ave., St. Louis 10, Missouri; CALAWAY H. DODSON, Instituto Botanico, Universidad de Guayaquil, Guayaquil, Ecuador.