中国兜被兰属植物的花粉形态及其分类意义

POLLEN MORPHOLOGY OF NEOTTIANTHE (ORCHIDACEAE) AND ITS TAXONOMIC SIGNIFICANCE

兜被兰属Ｎｅｏｔｉａｎｔｈｅ全世界共约１２种，中国均有分布，其中９种为我国所特有。本属花粉形态和组成都很特殊，它是由许多单粒花粉粘结在一起形成复合花粉———花粉小块，其形状一般为狭长的三棱锥体形。外壁表面具５种纹饰类型：（Ａ）近光滑，或具十分微弱的小凹陷；（Ｂ）外壁具穿孔状纹饰；（Ｃ）外壁具沟渠状纹饰；（Ｄ）外壁具拟网状纹饰；（Ｅ）具典型的网状纹饰。本属有些种类，例如：Ｎ．ｃａｌｃｉｃｏｌａ，Ｎ．ｍｏｎｏｐｈｙｌａ，Ｎ．ｐｓｅｕｄｏｄｉｐｈｙｌａｘ和Ｎ．ｃｕｃｕｌａｔａ等４种在分类上还存在许多问题，有些分类学家把Ｎ．ｃａｌｃｉｃｏｌａ，Ｎ．ｍｏｎｏｐｈｙｌａ，Ｎ．ｐｓｅｕｄｏｄｉｐｈｙｌａｘ３种均归并于Ｎ．ｃｕｃｕｌａｔａ。孢粉学资料表明上述４个种花粉特征完全不同，因此，上述４种仍应各自独立为种。最后，强调指出Ｎ．ｃａｍｐｔｏｃｅｒａｓ的花粉形状和外壁纹饰等特征在本属为特殊类型。

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.