Ptilidium pulcherrimum (G. Weber) Vainio (Hepaticae:Ptilidiaceae) - An Addition to Indian Bryoflora

The genus Ptilidium Nees was recorded for the first time from India by Mitten (1861), who described two species, viz. Ptilidium ciliare (L.) Hampe, and P. trichophyllum Mitt. [now treated under a separate genus as Blepharostoma trichophyllum (L.) Dumort.] based on the specimens collected by Sir J.D. Hooker from Sikkim. In the present state of our knowledge the genus is represented world over by three species, viz. P. ciliare (L.) Hampe, P. pulcherrimum (G. Weber) Vainio and P. californicum (Austin) Pearson (Stotler & Crandall-Stotler, 2005), of which only P. ciliare was known from India (Mitten, 1861; Chopra, 1943; Parihar & al., 1994; Singh & al., 2008). In a recent exploration in North Sikkim, some interesting corticolous specimens of the genus were collected with undifferentiated stem cells, 3-4(-5)-lobed leaves with the dorsal lobe 6, 10 cells wide at base and the dorsal sinus descending up to 2/3, 4/5 of leaf length, hence distinct from P. ciliare. A subsequent literature review (Macvicar, 1926; Schuster 1966; Paton, 1999) revealed it to be Ptilidium pulcherrimum (G. Weber) Vainio, earlier known from China, Japan, Europe and North America. The same has been described and illustrated here to facilitate its easy identification in Indian flora.