Taxonomic revision of the Lycopodiaceae in Southeast Asia : final report

Abstract

The Lycopodiaceae sensu lato is one of the large family of vascular plants comprising about 480 species. Treatment of the genera in this family is rather different among botanists ranging from a single genus, i.e. Lycopodium s.l. to 15 genera. Phylloglossum Kunze, is usually recognized as a distinct genus and family, Phylloglossaceae due to its unique characters and endemics to Australia. The most recognized classification segregated members of the Lycopodiaceae into three genera, namely Huperzia Bernhardi, Lycopodiella Holub, and Lycopodium L. s. str. The purpose of this study was to find additional evidences to support the separation of Lycopodiaceae from south-east Asian countries into one or more than one distinct genera. Four hundred and nine herbarium specimens (OTUs) from 7 species which represent the three segregated genera, were subjected to cluster analysis and discriminant analysis. Based on 16 quantitative characters and supported by 5 qualitative characters, cluster analysis strongly indicated the presence of three distinct groups within the studied specimens. This was accomplished by conducting a series of discriminant analyses using groups from the result of cluster analysis and the result was confirmed. It was found that 5 characters, i.e. sporangium shape, distance between two whorls, leaf thickness, width of sporangium, and diameter of apical shoot collectively supported the segregation of the 3 groups of genera from the Lycopodium s.l. So far, 25 species of Huperzia, 2 species of Lycopodiella and 8 species of Lycopodium s. str. were recorded in South-East Asia, while Thailand has 13 species of Huperzia, 1 species of Lycopodiella and 3 species of Lycopodium s. str. The following 8 species:- Huperzia cryptomerina (Maxim.) Dixit, H. dalhousiana (Spring) Trevisan, H. goebelii (Nessel) Holub, H. laxa (C.Presl) Trevisan, H. pulcherrima (Hook. & Grev.) Pichi-Serm., H. tetrasticha (Kunze) Holub, Lycopodium casuarinoides Spring and L. complanatum L. are new records for Thailand.