XVI International Botanical Congess
Pollen grains of seed ferns from Permian deposits of Russian platform were investigated. Both external morphology and ultrastructure of studied pollen are extremely varous: asaccate, bisaccate, monosaccate, with distal groove and without aperture. Ectexine is homogenous, almost homogenous, granulate and alveolate. Endexine is homogenous, fine-grained and lamellate. The morphological variety supports the taxonomical diversity.