FRUIT STRUCTURE OF THE GENUS CASSINOPSIS SOND (ICACINACEAE) IN AFRICA

Fruit development and structure of the two African species of Cassinop sis were examined by light microscopy. Both species are characterized by drupes: ovate-oblong, laterally compressed and yellow-orange in C. ilicifolia, oblong and black in C. tinifolia. The exocarp is uniseriat e and develops solely from the outer epidermis of the ovary. A parench ymatous mesocarp with vascular bundles and scattered druse crystals of calcium oxalate is derived from the ground tissue of the ovary wall. A uniseriate parenchymatous (C. ilicifolia) (lignified in C. tinifolia ) endocarp s. str. develops from the inner epidermis of the ovary wall . A lignified stone is derived mainly from the inner zone of the mesoc arp. The outer surface of the stone is of taxonomic significance, bein g smooth in C. ilicifolia and longitudinally ribbed in C. tinifolia. D ifferences in fruit structure. combined with other characters, suggest that the two African species are not taxonomically closely related. T heir generic status requires further comparative study, particularly w ith species of Cassinopsis in Madagascar.