Comparative morphology, anatomy and chemotaxonomy of two Cissus Linn. species

The systematics of plant taxa may be done using an integrated assessment of their morphological, anatomical, phytochemical and genetic characteristics, which may ultimately contribute to their sustainable utilization and value. This study adopts chemotaxonomy, morphometry and anatomical investigations to differentiate two Cissus species—Cissus populnea and Cissus rubiginosa. Results suggest only the leaves of C. rubiginosa contain flavonoids, whereas C. populnea leaves and roots contain starch, which is absent in the leaves and roots of C. rubiginosa. Saponin is present in the root of C. populnea and absent in C. rubiginosa root. The ground product of C. populnea root is light brown and dark brown in C. rubiginosa. Crude lipid content is higher in C. populnea than in C. rubiginosa in all the assessed parts. The leaf anatomy of both C. rubiginosa and C. populnea is isobilateral. However, more intercellular air spaces were observed in the leaf tissues of C. rubiginosa than in C. populnea. In addition, the adaxial leaf surface of C. populnea suggests an anomocytic stomata type with a conspicuous nucleus and starch grains in the parenchyma cell, whereas no visible stomata were observed in C. rubiginosa. The presence of trichomes in C. rubiginosa is notable, but a similar feature is absent in C. populnea. The stem anatomy of C. populnea reveals a solenostele–siphonostele arrangement, whereas C. rubiginosa shows a siphonostele arrangement. The root anatomy of both Cissus species is similar, but differences were observed in their leaf base, upper and lower surfaces, and leaf margin. Although the yellow-coloured flowers are umbel in both species, the fruit type is drupe in C. populnea and berry in C. rubiginosa. In conclusion, both Cissus species assessed in the study are distinguishable by their phytochemical constituents, anatomical features and phenotypic characteristics.