Can Integrating Morphology and Anatomy Contribute to Species Identification of Salacia oblonga Wall. and S. reticulata Wight in Family Celestraceae?

Purpose: Due to the overexploitation of Salacia oblonga and S. reticulata, natural populations have declined and become near threatened. Limited information is available on these species for correct identification and variability.  Correct identification and variability are crucial for conservation purposes. Therefore, morphological and anatomical studies were carried out on these two species to identify and reveal their variability.
Research Method: A detailed vegetative (leaves, stem, root), fruit morphology and anatomical study of leaf, petiole, stem, and root using light microscopy and Scanning Electron Microscopy was undertaken to identify reliable, diagnostic features to differentiate the two species and study the diversity of these species correctly.
Findings and Values: The key takeaways are leaf arrangement, leaf margin, natural colour of the stem, presence or absence of lenticels, external root colour, shape and colour of the mature and ripe fruits, and number of locules and ovules, which are critical vegetative and fruit morphological characters in field identification, distinguishing the species. The shape and wing extensions in the petiole, arrangement of the invaginated ends of the vascular bundle of the petiole and midrib, deposition of cuticular materials around stomata on the abaxial leaf surface, and shape of the stomata complex were important traits for taxonomic purposes. Using identified important morphological and anatomical characteristics, which are useful for identification in the field, a dichotomous key was constructed to separate the two species.