Phytogeography of the Pteridophytes in Peninsular Thailand

Abstract

The pteridophytes of Thailand have recently been studied intensively in the course of the Flora of Thailand project. I have participated in this project and have enumerated some 620 species of pteridophytes from this country. Concerning the phytogeography of Thailand, I have already discussed the species known from the northern part of this country, with special reference to the pteridophytes (Iwatsuki, 1972). It was concluded in that paper that northern Thailand belongs to the extreme southernmost part of the Sino-Himalayan region; the pteridophytes of peninsular Thailand, on the contrary, belong to the Malaysian phytogeographical element. At the beginning of this century, Ridley in 1913 and in several other papers published on the phytogeography of northern Malaya and lower Siam, chiefly based upon his own field observations; his data, however, are insufficient to compare with those available at present. In his comprehensive book on Malayan ferns, Holttum (1954) noted the distribution of Malayan ferns in lower Siam.