Principal modes of infoldings in tricolp(or)ate Angiosperm pollen

Abstract

Angiosperm pollen grains can absorb or release water quickly. The respective degree of hydration has great influence upon the actual pollen grain shape and is, to a certain extent, reversible (harmomegathic effect). In the hydrated condition the majority of pollen grains are usually spherical, but in the dry condition they are infolded in a highly variable manner. This paper demonstrates many kinds of infolding within dicotyledonous tricolp(or)ate pollen from several angiosperm families. In most cases the foldings are directionally oriented, but it is only possible to predict the final form in dry condition to a limited degree.