Taxonomic Revision of the Polypodiaceous Genera of India-I: Microsorium Link

Microsorium Link is generically distinct from Phymatodes Presl. Both the genera have hardly anything in common except for the fact that they have a common place under family Polypodiaceae. Microsorium species not only differ from Phymatodes in the position and distribution of sori (numerous small, never more than 2 mm wide, scattered in irregular rows) but also in possessing generally thin and membranaceous texture which is seldom the case in the other genus. The genus is represented in India by nine species. All of these occur in the Eastern Himalayas and in the Western Himalayas only one species, M. membranaceum is met with, while from. South India only three species, M. membranaceum, M. punctatum and M. pteropus (simple-leaved form)-are known. Except for M. punctatum, all the other are rather thinner in texture. Most of the taxonomic characters used for differentiating Kaulinia Nayar [typified by K. pteropus (Bl.) Nayar] from Microsorium are not constant. These are frequently shared by well recognised species of Microsorium such M. superficial, M. phymatodes and several others. The only dependable character in which Kaulinia differs from Microsorium is that of gametophyte and it will be attaching to much importanceto a single character if Kaulinia is recognised as a genus.