Spore Morphology of Pteridophytes from China IX.Botrychiaceae

The morphology of spores of 12 species(belonging to 3 genera)of Botrychiaceae from China was examined using scanning electron microscope(SEM).The results show that the spores are radially symmetrical with a triradiate aperture.The spores are often obtuse triangle or approximately rounded in polar view and hemispheric or super hemispheric in equatorial view.The length of polar axis is about 20～34 μm.Spore length of equatorial axis is about 31～40 μm.The profile of spore ornamentation is formed by exospore.There is a layer of thin perispore overlays outside the exospore.The ornamentations of spores can be divided into 3 types:(1)Verrucate-rugulate:The spores bear verrucate-rugulate ornamentations in distal polar surface,which top surface is flat.The verrucae or the rugulae connect into strips or ornate;(2)Verrucate:The spores possess verrucate ornamentations with different size and the neighbor verrucae fuse into short strips or not.(3)Lophate:the spores bear lophate folds which formed reticulate ornamentations.From spore morphology,ornamentation type and sporoderm structure,it is concluded that the discrepancies between species inner each genus are obvious.But,the discrepancies of species between the 3 genera are less distinct.Thus,it is suggested that 3 genera in Botrychiaceae should be combined into one genus,i.e.Botrychium,which can be divided into 3 sections.