Taxonomic Studies on the genus Cissus L. (Vitaceae) present in Obio/Akpor Local Government Area of Rivers State, Nigeria
This study was aimed at addressing the problematic taxonomy of the genus Cissus L. using three species namely; Cissus aralioides (Welw. ex Bak.) Planch, Cissus petiolata Hook.f and Cissus lageniflora Gilg and Brandt found in Obio/Akpor Local Government Area of Rivers State. The investigation was carried out using morphological, anatomical, epidermal and phytochemical lines of evidence. Macromorphology results showed that Cissus aralioides, Cissus lageniflora and Cissus petiolata matured leaf possess digitately compound leaf type, trifoliate compound leaf type and simple leaf type respectively. Micromorphological results showed that all studied species were hypostomatic with anomocytic stomata type present in the abaxial surface of all species. Epidermal cell shape of the adaxial and abaxial surface of all species were pentagonal and irregular to polygonal respectively. Transverse sections of the petiole of studied species shows an arranged and open vascular bundles in all species, variations where however seen in the number of vascular bundles. Methanolic extract of the three cissus species studied revealed the presence of secondary metabolites like; Phenols, Alkaloids, Aglycone Glycosides, Cardiac Glycosides, Steroidal Aglycone Glycosides in the stem and leaf of all species. The results obtained shows that all studied species show diverse characteristic differences but these differences are not adequate and convincing enough to separate them into different genera but it shows that that Cissus aralioides and Cissus lageniflora are more closely related than they are to Cissus petiolate. Moreover, more species and other lines of evidence should be used in future research. A dendogram to the relatedness of the species and a dichotomous bracketed key to their identification is provided.
Keywords: Cissus species, Taxonomy, dichotomous key, Dendogram