Comparative pollen morphology of Calycanthaceae for their taxonomic implication

The pollen morphology of four species of Calycanthaceae is described based on the observation of scanning electron microscopy and light microscopy. All pollens are monad, large grain category. The pollen grain was elliptic with disulcate. Surface ornamentation is smooth. Pollen grains of each species are from the genus Sinocalycanthus, Calycanthus, Chimonanthus and Idiospermum. The basic shape of the pollen grains is elliptical. The pollen is spheroid in Calycanthaceae except in Idiospermum, which represent boat-shape. The circular shape was in polar views in Chimonanthus but equatorial shape in Sinocalycanthus. Idiospermum and Chimonanthus were smooth exine with micro-perforation but rugose exine in Sinocalycanthus and Chimonanthus.