Pollen morphology of Chinese Glochidion (Phyllanthaceae) and its taxonomic implications.

The pollen morphology of twenty-five Chinese species belonging to two sections of Glochidion and one species from Phyllanthus subgen. Phyllanthodendron was examined using scanning electron microscopy (SEM). The results showed that pollen grains of Glochidion are isopolar, spheroidal to rarely subprolate in shape, (3)4-5(6)-colporate in aperture pattern, and tectate-reticulate to tectate-rugulate in exine ornamentation. Fusion of colpus ends was observed in some pollen grains of G. pseudo-obscurum and G. wrightii. The pollen grains of Phyllanthus dunnianus are similar to those of Glochidion species in their spheroidal shape and four-colporate aperture pattern, but are slightly larger in size, and show tectate-perforate exine ornamentation. In Glochidion, pollen morphology appears to be useful for distinguishing several macromorphologically similar. Additionally, palynological characters provide evidence for the taxonomy of the supergenus Phyllanthus s.l. [ABSTRACT FROM AUTHOR]