Studies on pollen morphology of the wild peony

The pollen morphology of 23 populations from 9 species in Sect. Moutan belonging to Paeonia has been examined with scanning electron microscope. The pollen grains are usually 3-colporidate, prolate, occasionally subspheroidal or perprolate and the pollen size is (22.7-46.4)μm×(13.6-29.9) μm. Sculptural types of exine are presented as foveolate, reticulate, wide-reticulate, rugulate-reticulate, rugulate, and so on. The results indicate that there exists a relation between pollen morphology and the externals of plants; the pollen morphology is different when the wild peony lives in changed environment. So pollen morphology is of some significance for a better classification of Sect. Moutan in Paeonia and more studies will need to be conducted for a better understanding of the phylogeny of the Sect. Moutan.