Phalaenopsis orchids are among the most widely cultivated and economically important ornamental plants worldwide. Orchid floral organ identity is controlled by specialized MADS-box protein complexes, yet the cooperative roles of A/E-class genes in perianth differentiation are not fully understood. Here, Hsu et al. confirm that the A/E-class gene OAGL6 interacts with the E-class genes PaSEP1/3 to form advanced SP and L complexes that regulate sepal/petal and lip identity in orchids. Further, their combined silencing causes severe leaf-like transformations of sepals, petals, or lips, thereby expanding the current perianth (P) code model.