Abstract: The spores of 5 species and 1 subspecies of Sphagnum in China were examined under LM and SEM, and one of them under TEM. All of the above spores are radial symmetrical, tetrahedral, rounded-triangular in polar view and 36.1-55.7 μm in diameter. Among them, the size of the spores of S. cuspidatum is the largest. Trilete is distinct, narrow and slightly curved, ca. 1/3-1/2 of the spore radius, margo very distinct under SEM, perine with gemmae and verrucae. The sporoderm of Sphagnum contains perine, exine and intine. On the basis of spore morphology, the point of view that Sphagnum is a primitive genus in mosses is supported. In sporo-pollen analysis the spores of Sphagnum are easily confused with some spores of ferns.

Key words: Sphagnum, Spore morphology, Sporoderm structure