杨树广布于用、亚、北美。其种类繁多,世界上约有100余种,我国有60多种,分布在北纬23°—53°34′,东经80°—134°范围内。杨树是北温带速生用材树种,在缺森林的国家已成为木材的源泉。目前,对杨树的分类主要是以外部形态特征为依据。为了探索其微观形态特征——花粉在分类学上的意义,我们进行了这项观察。关于杨树花粉形态的研究,国内报道很少。仅见到对杨树花粉的简单描述和对青杨(Populus cathayana Rehd.),钻天杨(Populus nigna var.italica Dur)、小叶杨(Populussimonii Carr.)较详细的形态描述并附有照片[1,2,3]。这些观察仅是在光学显 Poplar widely used, Asia, North America. There are more than 100 species in the world and more than 60 species in our country. They are distributed in the latitude 23 ° -53 ° 34 ’and the longitude 80 ° -134 ° East. Poplar is a member of the north temperate rapid-growing timber species, in the absence of forest countries have become the source of wood. At present, the classification of poplar is mainly based on external morphological characteristics. In order to explore its microscopic morphological characteristics - the taxonomic significance of pollen, we conducted this observation. About poplar pollen morphology, few domestic reports. Only a brief description of the poplar pollen and the more detailed morphological descriptions of Populus cathayana Rehd., Populus nigna var.italica Dur and Populussimonii Carr. , 3]. These observations are only in optical sign