Kalanchoe ceratophylla (Crassulaceae): The True Identity of Sidingin, a Medicinal Plant From Sumatra, Based on Morphological and Molecular Evidence

Kalanchoe species is a plant that contains secondary metabolites that are beneficial for human health. However, the systematics of species in the genus Kalanchoe are often debated because these plants have many variations that easily cross between species and can reproduce asexually with adventitious buds. Previous studies have revealed that Kalanchoe ceratophylla Haw. is often misidentified as Kalanchoe laciniata. Therefore, the reidentification of K. ceratophylla (Crassulaceae) as the correct identity of sidingin, a medicinal plant widely used in Sumatra, challenges the prior identification of the species as K. laciniata. This study is aimed at determining the true identity of sidingin, a medicinal plant locally used in Sumatra, Indonesia, and traditionally recognized as K. laciniata. Specimens of sidingin were collected from Sumatra and analyzed using morphological and molecular approaches to clarify its taxonomic classification. The morphological analysis revealed that sidingin exhibits pinnately lobed leaves and other distinct characteristics, which prompted comparison with documented descriptions of Kalanchoe species. Molecular analysis, accomplished through ITS sequencing, indicated a 94.60% identity match with Kalanchoe miteja, supporting the morphological findings. The resulting phylogenetic tree positioned sidingin within the same clade as commercially available samples of K. ceratophylla, suggesting a potential reclassification of sidingin as K. ceratophylla. This study provides new insights into the distribution of Kalanchoe species in Sumatra, documenting it as a new record only recently discovered in this region. Furthermore, through integrating morphological and molecular evidence, this study confirms that sidingin is K. ceratophylla.