Thesis (M.Sc.)--Chulalongkorn University, 2008

Diversity of ferns and fern allies at Khao Nan Yai, Nakhon Si Thammarat Province was carried out from July 2007 to April 2008 at elevations ranging from 330 to 1,385 m above mean sea level. A total of two hundred and twenty one specimens were collected. These specimens were identified and classified into 131 species, 58 genera and 24 families. Among these 11 species in 2 genera are fern allies, while 120 species and 3 varieties in 56 genera were ferns. The most common families were Polypodiaceae, Hymenophyllaceae, Dryopteridaceae and Woodsiaceae which included 23, 12 and 10 species, respectively. The collected species can be further classified in to 45 terrestrials and 1 variety, 37 epiphytes and 2 varieties and 14 lithophytes. However, 35 species thrived in more than one habitat. It can be concluded that 68 species were found in tropical evergreen forest, and 46 species grow naturally in hill evergreen forest. Moreover, 17 species grew in both forest types. It is noted that Ctenopterella khaoluangensis (Tagawa & K. Iwats.) Parris is the only endemic species for Thailand. Five species are new records for Thailand, i.e. Cyathea glabra (Blume) Copel., Cyathea hymenodes (Willd.) Sw., Huperzia coralia (Spring) J. Holub, Huperzia hippuris (Christ) J. Holub and Hymenophyllum treubii Racib. Key to the genera and the species were constructed. Full Description, together with ecological data, distribution, local name, and photographs of each species were prepared. The voucher specimens are deposited at the Professor Kasin Suvatabhandhu Herbarium, Department of Botany, Faculty of Science, Chulalongkorn University (BCU) and the Forest Herbarium (BKF), National Park, Wildlife and Plant Conservation Department.