Three new additions to the moss flora of Sri Lanka

Mosses (Phylum Bryophyta) comprise the most speciose group of bryophytes (liverworts, mosses, hornworts) and consist of about 13,000 species worldwide. Owing to its high level of topographic and climatic heterogeneity, the tropical island of Sri Lanka supports a luxuriant growth of mosses. Compared to other groups of plants in the country, mosses remain as a poorly researched group. Lack of proper taxonomic studies and scarcity of literature sources including locality details hamper further research in the field of bryology. Present study was carried out to explore the diversity of mosses in some selected localities of Sri Lanka. Fresh samples of mosses were collected from different localities including Horton Plains National Park, Loolkandura Conservation Forest, Kanneliya Forest Reserve and Badagamuwa Conservation Forest. Samples were observed for their morphological and anatomical characters using dissecting, compound and scanning electron microscopes. Specimens were identified following recent classification systems, using the most recent taxonomic keys, and monographs. The study identified three species records new to Sri Lanka including Brachymenium capitulatum (Mitt.) Kindb., Ctenidium pinnatum (Broth. & Paris) Broth. and Fissidens crassinervis var. laxus (Sull. & Lesq.) A. Eddy. Descriptions of these new species along with photo plates are provided. With the addition of 03 new records the total number of mosses recorded in the island increases from 572 to 575.


INTRODUCTION
Sri Lanka (formerly Ceylon) is an island country lying in the Indian Ocean. The island is one of the most diverse regions in South Asia and is recognized as one of the world's biodiversity hotspots along with the Western Ghats of India (Ashton et al., 1997). Owing to its high level of topographic and climatic heterogeneity, Sri Lanka supports a luxuriant growth of a remarkably rich bryophyte (liverworts, mosses, hornworts) flora (Geffert et al., 2013;O'Shea, 2003;Ruklani and Rubasinghe, 2015). In contrast to the wellstudied higher plant flora of Sri Lanka, bryophytes are still poorly explored, mainly due to their small size and difficult taxonomy (O'Shea, 2003;Rubasinghe and Long, 2014;Ruklani and Rubasinghe, 2013;Ruklani and Rubasinghe, 2015). According the recent checklists, the island harbours 327 species of liverworts Rubasinghe, 2014), 560 mosses (O'Shea, 2002) and five Hornworts .
Of the three phyla of bryophytes: Marchantiophyta (liverworts), Bryophyta (mosses) and Anthocerotophyta (hornworts), mosses are the most species rich group, including more than 13,000 species worldwide (Crandall-Stotler and Bartholomew-Began 2007;Goffinet et al., 2009). Foundation for studies on mosses in Sri Lanka was laid down during the British colonial period (details in Rubasinghe and Long, 2014). Alexander Moon (1817 -1825) was the first to collect Sri Lankan bryophytes, andsome of his specimens deposited at the Natural History Museum, UK, have not been studied or published yet (O'Shea, 2003;Rubasinghe and Long, 2014). A detailed description of contributions made by early scientists and explorers is given in Rubasinghe and Long (2014). A checklist compiling all the published literature was published by Brian O'Shea (2002). O'Shea's checklist recorded 60 families, 174 genera and 560 species of mosses from Sri Lanka. However, this checklist has not been updated todate and the country lacks a specimen-based checklist or a Flora of mosses. However, this checklist has not been updated to-date and the country lacks a specimen-based checklist or a Flora of mosses. Therefore, for most of the published taxa of mosses, locality details and descriptions are lacking and more localities still remain underexplored for bryophytes. However, a few contributions to the moss flora have been made since O'Shea's checklist.

MATERIALS AND METHODS
A series of taxonomic surveys were conducted at different geographic localities in Sri Lanka including Horton Plains National Park, Loolkandura Conservation Forest, Kanneliya Forest Reserve and Badagamuwa Conservation Forest. Fresh samples of mosses were collected and thoroughly surveyed for morphological and anatomical characters. Specimens were identified using taxonomic keys, descriptions and monographs and authenticated using type descriptions and/or specimens. Voucher specimens were prepared and deposited at the National Herbarium Peradeniya (PDA).  (Fig. 1).
Distribution-Ctenidium pinnatum is also reported from China, Japan, Taiwan and Vietnam (Zhang et al., 2016;Higuchi, Yao and Lin, 2012) and here from Horton Plains National Park, Sri Lanka.

DISCUSSION AND CONCLUSION
The four selected localities explored during the study revealed a considerable diversity of mosses including 23 families, 46 genera and 63 species. Calymperaceae, Fissidentaceae, Leucobryaceae, Meteroriaceae, Neckeraceae, Bryaceae, Dicranaceae, Thuidiaceae and Sematophyllaceae were the commonly encountered families during study. Horton Plains National Park comprised the highest species diversity and luxuriant growth of mosses while Badagamuwa conservation Forest showed the least species diversity and sparse growth of mosses. Deforestation, clearance of roadsides and climate change are main threats to the moss flora of Sri Lanka. Although Sri Lanka harbors a high diversity of bryophytes, there is no specimen based checklist nor a "Flora" for bryophytes of Sri Lanka. Therefore, documents describing their morphology, identification methods, distribution patterns, locality and phonological details lacking for most groups of bryophytes including mosses. This scarcity of information and expertise in the field prevent further research carried out on this important group of plants within the country. Also, due to the same reason, it is a barrier to identify the important sites for bryophyte conservation. The study emphasizes the importance of identification and documentation of the existing bryophyte flora of the country so that necessary conservation measures could be implemented to conserve the existing taxa before they are disappeared from the country.