Abstract:Pollen grains of 58 species of Artemisia were observed under LM and SEM to verify the reliability of the classification of Artemisia species. The tricolporate pollen grains with reduced exine ornamentation of Artemisia species make them easy to be distinguished from species of other genera of Compositae. Based on exine ornamentation, the pollen grains of Artemisia can be divided into two types: type Ⅰ, the hasal part of spinule corrugate and extend, type Ⅱ, the hasal part of spinule nearly rounded. There are 4 subtypes in type Ⅱ. i.e. Ⅱ-1, with spinules arranged sparsely, interspinule granular, Ⅱ-2, with spinules arranged sparsely, but interspinules smooth, Ⅱ-3, with spinules arranged densely, interspinule granular; Ⅱ-4, with spinules arranged densely, but interspinule smooth. The results observed have proved useful in the study of systematics in Artemisia. The evolution trends and the affinity of sections in Artemisia are also discussed.
