keywords: Morphometry, Euphorbia, PCA, cluster analyses
A morphometric study of the six species of Euphorbia in some parts of Nigeria was performed. Quantitative features were measured, recorded and thereafter subjected to appropriate statistical analyses (principal components analysis and cluster analysis). Results from the data collected re used to explore variations among and within the selected species of Euphorbia, and cluster analyses were used to ascertain systematic groupings of the taxa. Results from the morphological examinations showed that the variation in leaf length, leaf width, internode length, petiole and internode lengths are diagnostic. The dendrogram revealed different levels of relationships among and within species of Euphorbia. Great affinity was observed between E. prostrata and E. thymifolia followed by E. hirta and E. hyssopifolia whereas E.graminea and E. heterophylla are distantly related to other species. The similarities observed among and within each collection of species of E. hyssopifolia, E.hirta, E. prostrata and E. thymifolia justifies why they are classified under the same subgenus Chamaesyce. Distribution wise, the species were found to be sympatric or allopatric.