Some aspects of the morphology and distribution of Microsoriurn linguaeforrne (Polypodiaceae)

Microsorium linguaeforme is reported for the first time from India. Its rhizome is slender, much elongated with a highly dissected stele and leaf gaps in a single median dorsal row. The characteristic branching pattern is a modification of the common pattern in Polypodiaceae, resulting from the displacement of leaf-associated branches and the precocious development of the most basal secondary branch of each primary branch. The first two or three leaves of juvenile plants have no associated branches; thereafter, abaxially-originating traces t o solitary branches are progressively displaced so that the branch trace is close to the preceding leaf trace. Stomata of adult leaves are Copolomesoperigenous and of juvenile leaves Eupolomesoperigenous. The spores are monolete and with a smooth exine. Spore germination is of the Vitiariatype and prothallial development of the Kauliniatype. It is concluded that M. linguaeforme is closely allied to Leptochilus and is probably parental to it.