THREE PALYNOLOGICAL PUZZLES

摘要

Three aspects of palynology in which core questions remain unanswered are reviewed. These are (1) the function of the huge range of types of exine sculpture of iso- and microspores that they share with many of those seen in angiosperm pollen; (2) the selective value of multiple apertures in eudicot pollen; and (3) the worldwide spread of very similar striate bisaccate pollen, apparently derived from at least three separate and very different gymnosperm plant groups in the Permo-Trias, when the macrofloras of that time show such strong biogeographic segregation.