MORPHOLOGICAL VARIATION IN ASPLENIUM TRUNCATUM BLUME (ASPLENIACEAE)

Asplenium truncatum Blume exhibits considerable morphological variation across its distribution in Malesia, which cause the name is used interchangeably with closely related taxa i.e. A. caudatum. This study examines the range of morphological characters within populations of A. truncatum specimens and evaluates diagnostic value of them. We used 91 herbarium specimens for 12 quantitative character measurements and three qualitative characters scoring that included in the morphometric analyses. Variations were found in frond architecture, pinna shape, and scale characters, which historically led to the recognition of morphotypes or varieties, including var. lobulatum and var. crenulatum. Principal Component Analysis (PCA) revealed that the variation among these morphotypes forms a continuous spectrum without clear morphological boundaries. These results indicate that the observed diversity represents phenotypic plasticity within a single species rather than distinct taxonomic entities.