in Sri Lanka - Ministry of Environment

DistributionLimited research has been conducted to identify distribution of pterdophyte flora in Sri Lanka.About 81% of pteridophyte specimens in the National Herbarium have been collected fromthe wet zone area of the country (Jayasekera and Wijesundara, 1993). The wet zone whichaccounts for only one third of the country’s total land area also contains almost all endemicpteridophytes except one species (Ranil et al., in prep.). Further, study on distribution patternof endemic pteridophyte flora of Sri Lanka revealed that those are more-or-less equallydistributed among the wet zone areas of the up, mid and low countries with 34, 31 and 32 taxa,respectively (Ranil et al., 2008a). Majority of endemic pteridophytes (78%) of Sri Lanka hadbeen collected from the Central Province where Nuwara Eliya district alone provided the highestnumber of endemic taxa collected with 34 taxa followed by Sabaragamuwa and Southernprovinces. Even though some species occur in a few districts, their known occurrence hasbeen limited only to a few isolated localities (i.e. Cyathea hookeri, C. sinuata, C. sledgei andC. srilankensis; Ranil et al., 2010a; 2010b). Long duration of rainfall and high relative humidityassociated with elevational gradient may be one of the reasons for the presence of highernumber of endemic taxa in the wet zone and the Central Province. In addition, close proximityto the Botanical Gardens of Peradeniya and Hakgala had also influenced a higher number ofspecies collections from the Central Province and Nuwara Eliya district.A B CEndemic and endangered tree ferns in lowland rainforests.A: Cyathea sledgei Ranil et al.,: A recently described new endemic tree fern species in KanneliyaMAB reserve.B: Cyathea srilankensis Ranil: A recently discovered new endemic tree fern species in Beraliyaproposed forest reserve.C: Cyathea sinuata Hook. & Grew.: The only known simple leaf tree ferns in the world.ABTwo endemic ferns species in southern lowland rainforests.A: Tectaria thwaitesii (Bedd.) Ching: An endemic fern species in roadside banks of Kottawa forestreserve.B: Oreogrammits sledgei (Parris) Parris: An endemic fern species grows on moist rock in Sinharajaworld heritage site.150