Coelogyne is one of the orchid genera that grows in the Liwa Botanical Garden, Lampung, Indonesia. The subsequent study aimed to characterize the Coelogyne different species samples based on the morpho-anatomical characteristics of the stomata. Six leaf samples of the different species, as collected, had the paradermal sections examined microscopically to observe their stomata. The key stomatal traits studied included their aperture width, stomatal length, width, density, and index, and the number of stomata. The results indicated that overall, the epidermal cell width was 9.25 μm, stomata length was 19.65 μm, stomata width was 17.09 μm, stomata density was 17.67 mm², and stomatal index was 1.045%. The phenetic analysis based on the dendrogram divided the Coelogyne different species samples into two clusters (A and B), with similarity indices of 1.60 and 0.90, respectively. Meanwhile, the PCA values (2.4 and 0.093) emerged as greater than 0.02, which shows the contribution value of each group. The presented results provide a sound genetic base for the identification and conservation of different Coelogyne species at the Liwa Botanical Garden, Indonesia, and the potential applicative value of stomatal characteristics in ex situ conservation and taxonomic classification of Coelogyne.

Keywords: Coelogyne, leaf anatomy, orchid conservation, PCA, phenetic analysis, stomatal morphology

Key findings: The different Coelogyne species samples showed varied morpho-anatomical characteristics. The most influential characters were the stomata density, stomatal opening width, and stomatal index. The phenetic analysis divided the Coelogyne species samples into two clusters (A and B), with similarity indices of 1.60 and 0.90 and PCA values of 2.4 and 0.093, respectively, emerging greater than 0.02.