Abstract

Microsorium membranaceum var. carinatum, a newly published variety, can be distinguished easily from the original variety M. membranaceum var. membranaceum by the stipe morphology. The cross section of stipes is triangular in the former， but semicircular in the latter. Here phylogenetic relationship of the two varieties was investigated based on the sequence analysis of chloroplast rbcL，rps4，trnL-trnF， and rps4-trnS intergenic spacers. Furthermore, the published relevant sequences from other ferns were also analyzed for the comparison of genetic distance. As a result, no sequence difference in the studied four cpDNA regions was found between M. membranaceum var. carinatum and M. membranaceum var. membranaceum, but some difference in the corresponding DNA fragments is present among other fern varieties. Hence, the status of Microsorium membranaceum var. carinatum as a distinct variety is not supported by the DNA analysis.