Studying morphological characteristics, anatomical structure of Melaleuca species, Callistemon citrinus and acacia auriculiformis

Abstract

Common morphology characteristics among the species Melaleuca cajuputi subsp. cajuputi, Melaleuca cajuputi subsp. cumingiana, Melaleuca alternifolia, Callistemon citrinus, and Acacia auriculiformis often cause confusion among them and complicate their application. This study aims to characterize the morphological features and anatomical structure of five species based on the plant morphological analysis method. The leaf anatomical specimens at the sites of stems, veins, and tips of leaves were performed by horizontal slicing, and dyeing carmin aluné–vert d’iode. Furthermore, the anatomy of flowers was analyzed based on their components at the pre-flowering stage. The results showed an identical morphology between these species. However, certain morphological differences are present such as the color of the bark, leaf size, flower color, the type of flower pre-anthesis. Differences in anatomical structure, namely the number of secretory cavities in the leaves and the color of the stamens. At a 95% confidence level, Acacia auriculiformis exhibits the largest leaf size, while Melaleuca alternifolia presents the smallest. Each species is characterized by distinct floral coloration: Melaleuca cajuputi subsp. cajuputi displays pale greenish-white flowers, Melaleuca cajuputi subsp. cumingiana has ivory-white flowers, Callistemon citrinus exhibits bright red flowers, and Acacia auriculiformis produces vivid yellow flowers. Notably, Acacia auriculiformis leaves lack secretory cavities, a distinguishing feature compared to members of the Myrtaceae family. These species can be differentiated based on external morphological characteristics, with floral color serving as one of the most distinctive and easily recognizable traits.