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Microtrichomanes, a controversial genus created originally to accommodate “intermediates” between Hymenophyllum and Trichomanes, was reassessed using molecular data in order to clarify the systematic position of the species assigned to it. The results strongly suggest a polyphyletic origin for Microtrichomanes, with most of the species being placed in Hymenophyllum s.l., in spite of their having the cup­shaped involucre which is the primary taxonomic character of Trichomanes s.l. Based on this result, some new combinations are made herein for the species formerly attributed to Microtrichomanes; and an updated dichotomous key and synonymic lists are provided.

The genus Phlegmariurus Holubis recognised more widely than originally proposed and is circumscribed to include both Neotropic and Palaeotropic epiphytic and terrestrial species of Huperzioid Lycopodiaceae that have isotomous shoots, lack bulbils in their sporophyllous shoots and have spores with convex lateral margins and foveolate-fossulate sculpture restricted to their distal surfaces. New combinations with Phlegmariurus are proposed for 81 species and existing combinations identified for 33 species originating from the Palaeotropics. This installs a generic circumscription that is consistent between the Neotropics and Palaeotropics. A lectotype is designated for the type species of the genus, Phlegmariurus phlegmaria (L.) T.Sen & U.Sen

Tree ferns are a remarkable group among the lycophytes and ferns. Geographical isolation is suggested as one of the main reasons for local endemism of tree ferns and the island of Sri Lanka has been identified as one of the best demonstration sites to observe this phenomenon. Despite its small size, Sri Lanka has a rich diversity and one of the highest levels of endemism of tree ferns in Asia. Their diversity here is considered as an unique and important gene pool in the world. The present eco-spatial survey is to study the diversity and ecology of tree ferns in Sri Lanka.The study identified nine tree fern species including one new record of an adventive species. The species are Cyathea hookeri, C. sinuata, C. sledgei, C. srilankensis, C. walkerae, C. crinita, C. gigantea, C. australis and Dicksonia antarctica. Of these, the first five species are endemic to Sri Lanka. Dicksonia antarctica and Cyathea australis are exotic and naturalised in forest clearings in Piduruthalagala forest. Cyathea hookeri, C. sinuata, C. sledgei and C. srilankensis are confined to limited populations in lowland rainforests (62-550 m). Cyathea walkerae is distributed in a wide elevational range throughout the wet zone (30-2,300 m), whereas C. crinita shows a restricted distribution pattern at a high altitude range (1,800-2,400 m). In this study C. gigantea was recorded additionally from lowland rain forests, though it was previously reported to be confined to submontane and montane ecosystems. The results of this study provide baseline information on the distributional ecology of Sri Lankan Cyathea species. It will be useful to assess their current conservation status and to formulate conservation guidelines for these remarkable and spectacular ferns so characteristic to Sri Lanka.

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