“…Corolla development, however, if unidirectional, is mostly abaxial → adaxial or the corolla lobes are initiated simultaneously. The first case is found in Gesneriaceae (Titanotrichum; Pan et al, 2002), Orobanchaceae (Agalinis, Rhinanthus; Armstrong and Douglas, 1989;Kampny and Canne-Hilliker, 1987), Phrymaceae (Mazus; Rawat et al, 1988; there is still some doubt as to whether or not the genus Mazus is to be included; Albach et al, 2009;Oxelman et al, 2005;Tank et al, 2006;Xia et al, 2009), and Plantaginaceae-"Scrophulariaceae" (Digitalis; Singh, 1979). The second case is found in Scrophulariaceae s.str.…”