The Indo-Burma region, due to its rich biological and environmental characteristics, has attracted numerous studies on the biodiversity of fern species. The genus Leptochilus (family Polypodiaceae) is known to have a widespread distribution across Southeast Asia, especially in Indonesia, Malaysia, and Indochina. However, the taxonomy, distribution, and diversity of Leptochilus on the islands within the region have not been extensively studied. Despite the species richness, the taxonomic features and systematics of this genus remain unclear, lacking a well-defined classification system for the species within it.
Through this study, the authors conducted field surveys in areas such as Java (Indonesia). The research collected fern samples from various regions, ranging from tropical forests to coastal areas. After analyzing and comparing the morphological characteristics of the collected samples, the study identified several new species of Leptochilus, while also clarifying the morphological variations of species within this genus. In addition to describing the morphology, the research team employed DNA analysis techniques to determine the taxonomic relationships among the species and construct a phylogenetic tree of the Leptochilus genus in the region.
The results of the analysis revealed a significant diversity in the morphological characteristics of the fern species in the Leptochilus genus, including differences in leaf shape, size, scale structure, and distribution. Notably, the leaf morphology varied, with forms ranging from simple leaves to compound, branching leaves. These characteristics provide the basis for a more detailed classification of the species in the genus Leptochilus, while also highlighting challenges in their future taxonomy. The distribution of Leptochilus species also showed distinct differences across islands, with some species found only on specific islands, while others have a broader distribution. These species primarily inhabit tropical forest areas, sometimes growing in humid soil environments or on moist rock faces.
By using genetic analysis methods, the authors also determined that many Leptochilus species are genetically closely related, though some species exhibit clear genetic distinctions, leading to the identification of 11 distinct lineages. These lineages show phylogenetic isolation from one another. The relationships of three old names, Leptochilus ovatus, L. pedunculatus, and L. pothifolius, were clarified, and investigations of their morphology and distribution confirmed that these 11 lineages represent 11 new species previously unknown to science. Interestingly, all of these 11 new species are endemic to the Indo-Burma Biodiversity Hotspot.
Below are some images of the newly described species:
Figure 1. Leptochilus vietnamensis Liang Zhang, N.T. Lu & Li Bing Zhang
Figure 2. Loài mới Leptochilus daklakensis Liang Zhang, X.M. Zhou & Li Bing Zhang
Figure 3. Leptochilus locii Liang Zhang, N.T. Lu & Li Bing Zhang
Figure 4. Leptochilus neolongipes Liang Zhang, X.M. Zhou, T.T. Luong & Li Bing Zhang
News: Lu Thi Ngan, Vietnam National Museum of Nature, VAST