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Studies on Pollen Morphology of Pulsatilla Mill.


 Pollen grains of 18 species of Pulsatilla in Ranunculaceae distributed
in Asia and Europe were examined by LM and SEM, and exine ultrastructure of tri-
colpate pollen grains of P. chinensis and of pantoporate pollen grains of P. campanella
was examined by TEM. Pulsatilla pollen is divided into four major types based on the
aperture character, i.e. tricolpate, di- and tricolpate, pantocolpate and pantoporate. The
revolutionary trend of pollen types is as follows: tricolpate→pantocolpate→pantopo-
rate.  Surface spinulate and perforate.  According to density and size of sptnulae and
distribution of perforation, the pollen grains of the genus can be divided into two gro-
ups.  Thin sections of P. chinensis and P. campanella show endexine  thickened  at
colpi and ora.  Ektexine consists of a foot layer, a collumellae layer and a continuous,
perforate tectum.  The columallae layer is thicker than foot layer and tectum.  Pollen
morphology of Pulsatilla is similar to that of Anemone, but different in the distribution
of spinules and perforation.  Pollen information supports Wang’s view about systema-
tic arrangment of species of Pulsatilla in China.


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