ANATOMICAL CHARACTERIZATION OF ROOTS OF SOME MEDICINAL PLANTS OF THE FAMILY EUPHORBIACEAE IN NIGERIA

This study has documented the root anatomical variability of some species of Euphorbiaceae in the Niger Delta region of Nigeria, as a means of providing information for quality assessment of herbal industry. Family Euphorbiaceae is also called spurge family consisting of about 322 genera and 7,700 species. Species are predominantly cosmopolitan with strongest representation in the humid tropical and subtropical regions of both hemispheres. Plants belonging to Euphorbiaceae family are widely used in Nigeria for various medicinal purposes. Based on this, seven species were selected for study from four genera which includes: genus Acalypha – A. hispidia and A. wilkesiana, genus Euphorbia – E. heterophylla and E. hirta, genus Jatropha – J. curcas and J. gossipifolia and the genus Manihot – M. esculenta. Transverse sections of the roots were obtained by free hand sectioning and submitted to double staining with methylene blue and safranin process for the anatomical study. Anatomical results of the roots revealed much variability among the species. Root characters such as the nature of the epiblema, cortex and vascular tissues are of high taxonomic significance. The secondary root has peridermis, parenchymatic cortex, collateral vascular system surrounded by sclerenchyma. The anatomical features are useful for dif­ferentiation among the species. This study will be helpful in correct identification and standardization of the plant material which is of medicinal importance.