Flower development in Antirrhinum majus L. (Scrophulariaceae) with a comment upon corolla tube formation

Abstract

The inflorescence apex is stratified and has a single layered tunica, bracts as well as all the floral organs develop acropetally. Except for stamens which are initiated with the activity of deeper layers of apex, all other floral appendages are initiated with the activity of second layer. On the basis of ontogenetic studies the floral organs have been homologised with the leaves. The adjacent calyx lobes develop and remain closely appressed and do not show post-genital fusion. Corolla tube is formed due to zonal growth preceeded by joint growth of hump on the abaxial face of stamen primordia and interprimordial region between petal primordia. Thus no post-genital fusion was observed. The placentae develop concomitantly with carpellary wall.