A taxonomic investigation of variation within ciassus quadrangularis L. in Kenya
Wahiti, Gituru Robert
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Using information from literature as well as records of localities on herbarim Specimen labels at the East African Herbarim, Nairobi (EA), and materials of Cissus quadrangularis L., Cissus cactiformis Gilg. And Cissue Quadrangularis Chiov. Were collected and new localities were sought. On the basis of the nature of their stem angles, the specimens of C. quadrangularis were sorted into two variants, A and B. Variant A has smooth stem angles ehile variant B has rough stem angles. The author has proposed that variants B be recognized as a new variety within C. quadrangularis. It is assumed that Variant A is the typical variety of C. quandrangularis. A map showing the distribution of the two variants in Kenya was prepared. The rough-edged variant B was found to be absent from the low-lying semi-arid regions of Northern Kenya. The variants were found occurring in distinct, separate populations but without separate geographical patterns. In only one locality a mixed population of both variants was observed. Using the t-test there was shown to be no significant different (P>0.05) between the means of measurements of dimension of various organs in the two variants. The stem angles of specimens of the two variants were studies under scanning electron microscope (S.E.M) yielding photomicrographs that showed a clear morphological difference between the two variants. The chromosomes of C. quadrangularis, C. cactiformis and C. quinquangularis were studies by acetopropionic staining methods. Somatic cells of the two variants of C. quadrangularis indicated a similar diploid chromosome number. Chromatographic analysis of the stem extracts of the two variants of C. quandrangularis indicated similar chemical composition. Herbarium specimens of C. quadrangularis prepared by different techniques were compared for shrinkage, retention of colour, and persistence of stem appendages. The appropriate technique for preparing herbarium specimens of C. quadrangularis has been identified and recommended. A pretreatment technique previously used for preparing herbarium specimens of Begonia species has been tested and recommended for treating specimens of C. quadrrangularis by botanists and other herbarium worker. The results of the investigation appear to support the hypothesis distinct kinds that can be recognized as taxa at infra-specific level.