Organization and Significance of Lenticels in Dicotyledons. I. Lenticels in Relation to Aggregate and Compound Storage Rays in Woody Stems. Lenticels and Roots

Abstract

Based on evidence obtained from 279 species and 35 varieties of dicotyledons and on a new procedure for the removal of epidermis and periderm, permitting of a more satisfactory study of lenticels and stomata, lenticular organs are classified as either transverse or longitudinal in accordance with the orientation of their fissures; such orientation in stems is correlated intimately with the nature of the storage ray within. Thus the more primitive types of aggregate or compound rays are confronted with transverse lenticels, whereas the less primitive are subtended by longitudinal lenticels. In contrast to stems, roots generally show transverse lenticels, in pairs, one on either side of each secondary root, a situation characteristic of young coniferous stems and all coniferous roots, thus indicating the conservative nature of the root. The intimate relation between the type of storage ray and the form of lenticel facilitates a satisfactory aeration of the living tissues within the stele, with the consequent maximum metabolic activity.