A STUDY ON DEVELOPMENTAL ANATOMY OF TWO KINDS OF GLANDULAR HAIRS ON THE LEAVES OF MENTHA HAPLOCALYX BRIG

The morphology and development of capitate and peltate glandular hairs on the leaves of Mentha haplocalyx Brig were studied with the help of thin section and a scanning electron microscope The results were as follows;The initial cells,which originated from the protodermal cells,created a basal cell,a stalk cell and an apical cell through two successive periclinal divisions The origination and early development of both types of glandular hairs were similar During the late development,the apical cell did not divide and therefore the capitate glandular hair with one secretory cell formed if the stalk cell rapidly enlarged longitudinally If the stalk cell kept meristematic,the apical cell would continue to divide anticlinally up to form 8 or 16 secretory cells of peltate glandular hairs Upon the secretory stage of glandular hairs,a large amount of essential oil accumulated between the cuticular layer and the wall layers below it However,the subcuticular space was not observed in the head of capitate glandular hairs Therefore,the type and function of glandular hairs were affected by the differentiation degree of the stalk cell during the development of glandular hairs