LEAF MICROMORPHOLOGY IN GENUS Alpinia (ZINGIBERACEAE)

Abstract

Leaf epidermal characteristics are essential for phylogenetic and taxonomic studies of many plants. Among the family Zingiberaceae, Alpinia is recorded as the largest genus. This study aimed to identify the leaf micromorphological characteristics of the genus Alpinia that can be used in species identification as supportive data in classification and also to determine the taxonomic value of their micromorphological characteristics. In fact, the genus Alpinia has been studied less in Malaysia and requires more supporting data for species identification. Hence, a study has been conducted on eight species of Alpinia, which are Alpinia assimilis, A. javanica, A. ligulata, A. malaccensis, A. mutica, A. pahangensis, A. petiolata, and A. rafflesiana. Characters such as epidermal cell shape, trichomes, and stomatal type and distribution were observed. The result from this study suggests that all the species studied are amphistomatic, which means the stomata are present in both the abaxial and adaxial surfaces of the leaf. All the stomas in the species studied are tetracytic. However, trichomes on the leaf surface can only be discovered in A. assimilis, A. malaccensis, A. rafflesiana, and A. pahangensis. Notably, all the trichomes possessed simple and unicellular types. In conclusion, studies on leaf micromorphology in the genus Alpinia have taxonomic significance and can be used in species identification and classification, especially at the species level.