Pharmacognostic Evaluation and Molecular Identification of Cinnamomum myrianthum Merr. Leaves

Introduction: Cinnamomum myrianthum Merr. is a narrowly distributed endemic species in the Philippines with limited scientific information on its botanical identity and quality attributes. This study was undertaken to establish the pharmacognostic profile of C. myrianthum leaves as a scientific basis for species authentication, standardization, and phytochemical and biological investigation. Methods: Mature leaves were collected, taxonomically authenticated, and evaluated using standard pharmacognostic procedures. Organoleptic, macro- and micromorphological, and physicochemical characteristics were determined, including moisture content, loss on drying, ash values, extractive values, and pH. Molecular authentication was further performed through chloroplast rbcL DNA barcoding, followed by sequence similarity analysis and phylogenetic reconstruction. Results: C. myrianthum leaves exhibited characteristic sensory features, including an olive-green lamina, distinct aromatic odor, glabrous texture, and mildly bitter taste. Morphological examination revealed opposite to sub-opposite, petiolate leaves with triplinerved venation and a typical dorsiventral leaf anatomy. Physicochemical evaluation showed total ash (4.58%), acid-insoluble ash (1.94%), moisture content (7.29%), loss on drying (6.81%), and slightly acidic pH (5.37), all within acceptable limits for crude herbal materials. DNA barcoding generated a 606 bp rbcL consensus sequence with 44.55% GC content, showing >99.8% sequence similarity with authenticated Cinnamomum species and confirming its taxonomic placement within the genus. Conclusion: This study establishes the first pharmacognostic reference standards for C. myrianthum and provides essential baseline data for its botanical authentication, quality control, and future phytochemical and pharmacological studies, supporting its scientific utilization and conservation as an endemic Philippine medicinal plant.