Dendrobium is a genus of orchids comprising more than 1,000 species, renowned for its aesthetic appeal and commercial value. Species identification can take place by observing morphological characterization to determine the relationship among the species. This study builds upon previous research by conducting a comprehensive morphological characterization of the Dendrobium collection at the Liwa Botanical Garden. The morphological characterization proceeded using 25 leaf and flower traits, followed by an analysis of character variations and species grouping using the principal component analysis (PCA) and unweighted pair-group method with arithmetic averaging (UPGMA). The eight Dendrobium leaf samples (D1 to D8) showed some similarities and differences in their morphological traits. PCA analysis divided the samples into two main groups; Group I has a contribution of 82.448%, while Group II has 12.505%. UPGMA analysis produced a dendrogram showing two main clusters, A and B, and subclusters based on the same morphological characters. Cluster A comprised D7, D8, D6, and D5, while cluster B consisted of D2, D4, D3, and D1. Morphological grouping enunciated the relationship among the studied Dendrobium samples, and the highest similarity index indicated close kinship. Dendrobium species with morphological characterization can aid as an effort to preserve orchid germplasm in the Liwa Botanical Garden.

Keywords: Dendrobium, kinship analysis, morphological characterization, PCA, UPGMA

Key findings: Identification based on morphological traits, such as leaves and flowers, allows an accurate differentiation among the species. Morphological characterization of Dendrobium species is essential for supporting the breeding program and conservation of orchid germplasm in the Liwa Botanical Garden.