Involved in the dorsovental asymmetry of flowers. Promotes ventral identity. Detected in the apical inflorescence meristem, in bract primordia arising in its periphery and in floral meristems produced in the axils of bracts (stages 0-3). From stage 3 to stage 8, detected in all floral organs irrespective of their dorsoventral positions. From stage 9, barely detectable in bracts, sepals, and stamens. In the corolla, however, expression was maintained and enhanced in some regions. Within ventral and lateral petals at stage 9, asymmetric pattern of expression with high levels of transcripts in the inner epidermis of the furrow and very reduced levels in the remaining cell layers. In the dorsal petals, from stage 9 onward, detected but with a more even distribution across cell layers than in the ventral petal. The petals are fused at the base, forming a tube that ends in the lobes.