Except for some differences in exine ornamentation and pollen size, there is no great evolutionary divergence among genera in pollen morphology.
总体来讲，花粉没有大的演化分异，只是表面纹饰和花粉大小有一定的差异。
2
Method: Pollen exine ultrastructure were compared for 18 populations growing under in the same environment by means of scanning electron microscope (SEM).
方法：借助扫描电镜对栽培在同一生境下的18个半夏居群的花粉形态、大小及表面纹饰等特征进行观测比较。
3
Alveolae of the proximal exine are smaller and less regular in form than those at equatorial region.