AN ANATOMICAL STUDY OF THE SUBTERRANEAN ORGANS OF EUPHORBIA ESULA IN RELATION TO ITS CONTROL

Abstract

Young roots of Euphorbia esula exhibit a structure similar to that of a typical dicotyledonous species. In older roots, wood comprises as much as two-thirds of the total tissues. Cork is several layers thick, and lenticels are of open type. Pericyclic meristem forms a continuous ring any part of which may give rise to lateral organs. The primordia of lateral roots and shoots cannot be distinguished morphologically from each other until they have emerged from the parent organ. In the case of stems the lateral buds originate endogenously from the internodes but exogenously at the nodes. The subterranean organs of the species are supplied with simple, nonarticulated, and branched laticifers. Almost all parenchyma cells including the laticifers are filled with starch grains. The significance of these anatomical features with respect to the control of the species is discussed.