POLLEN MORPHOLOGY OF NEOTTIANTHE (ORCHIDACEAE) AND ITS TAXONOMIC SIGNIFICANCE

The genus Neottianthe (Orchidaceae) consists of about 12 species in the world, of which all are found in China and nine are endemic to China. The pollen morphology of this genus is very specific in shape and composition. All pollen grains in Neottianthe are of a compound pollen grain, called massula, in which of many monad pollen grains adhere together. A massula is usually long and narrow trigonous cone in shape. Pollen grains can be divided into five types according to ornamentation, of exine surface: (A) pollen surface almost smooth, or very obscurely fossete, (B)perforate, (C) fossulate or foveolate, (D) reticuloid, and (E) typically reticulate. Neottianthe. calcicola, N. monophylla, N.pseudo diphylax and N. cucullata have been merged into one species, N. cucullata, by some taxonomists. This treatment is not supported by the pollen morphological data, because pollen morphological characteristics of above mentioned four species are different from each other. Therefore, pollen morphology shows that they are all independent at the specific level. Finally, it must be stressed that N. camptoceras is uniquite in the genus Neottianthe for its pollen shape, size and surface ornamentation of pollen exine.