Abstract: The pollen morphological characteristics of Artemisia wudanica were observed and described in details by using scanning electron microscopy (SEM) technique to explore the dimorphic characteristics of the pollens and improve the fine characteristics of pollen morphology. The results showed that there were two shapes of the pollens:the long spherical shape and the spherical shape,and the pollen morphology had obvious dimorphic characteristics. The pollens with long spherical shape were oval in the equatorial view and three-lobed circular in the polar view;the germination organ was a three-hole groove type;The size was 23.28 μm×13.73 μm in average;The pollen surface had a thorny-granular composite ornamentation. The pollens with spherical shape were spherical in the equatorial view and tri-split circular in the polar view;The germination organ was also a three-hole groove type;the size was14.85 μm×13.80 μm in average;The pollen surface had a thorny-granular composite ornamentation. Except for pollen size,polar axis/equatorial axis ratios (P/E),the overall morphological characteristics of long spherical pollen and spherical pollen were basically the same,and the main difference was in subtle characteristics,such as thorny size,and the density of thorny and granular.

Key words: Pollen grains, Morphology, Dimorphic characteristics, Artemisia wudanica

摘要： 以内蒙古特有乡土沙生植物乌丹蒿（Artemisia wudanica）为研究对象，采用扫描电镜（Scanning Electron Microscopy，SEM）技术，对其花粉形态进行了详细的观察描述，探索其花粉形态的二型性特点，完善其花粉形态细微特征。结果表明：乌丹蒿花粉粒有长球形和圆球形之分，花粉形态存在明显的二型性特征。长球形花粉赤道面观为椭圆形，极面观为三裂片圆形；大小平均为：23.28 μm×13.73 μm；萌发器官为3孔沟类型；表面纹饰为刺状-颗粒状复合纹饰。圆球形花粉赤道面为圆球形；极面为三裂圆形；萌发器官也是3孔沟类型；大小平均为：14.85 μm×13.80 μm；表面纹饰亦为刺状-颗粒状复合纹饰。除花粉粒的大小、极轴与赤道轴的比值（Polar axis/Equatorial axis，P/E）不同外，两种类型的花粉总体形态特征基本一致；细微性状主要差异表现在表面纹饰中刺的大小及刺与颗粒的排列密度等方面。

关键词: 花粉粒, 花粉形态, 二型性, 乌丹蒿