Pollen spore morphology and plant evolution

Abstract

Spores and pollen grains both are resistant to environmental stress and diagnostic by virtue of the unique exine characteristics, by which it has emerged as a reliable tool in evolutionary biology, both of fossils and present day plants, at various taxa levels. “Sporae Dispersae” being the only morphological material reflecting continuity of evolutionary lineage through geological time, there is new scope for its application in fixing stratigraphic successions and phyletic origins. The triphyletic theory of the origin and evolution of angiosperms has been explained to demonstrate the value of pollen grains and spores in phylogenetic taxonomy, and further, the emerging areas of application of the principles of morphological evolution of pollen grains have been indicated.