SEM of the extrafloral nectary ontogeny of V. adenantha . (A) globose secondary axis of the inflorescence with nectaries in different stage (s1, stage 1; s3, stage 3; s4, stage 4). (B) Stage 1. Tectrix bract with simple trichome (st) and glandular trichome (gt). (C) Stage 2. Scar of the tectrix bract α and β bracteoles (α, β) with simple and glandular trichomes, bud (f) and ring (r). (D) Stage 2. Scar of the tectrix bract, scar of the α bracteoles, β bracteole, bud with calix lobes (k) and ring. (E) Stage 3. Longitudinal section of an EFN with rests of the abscission zone (a). (F) Stage 3. Middle-moon shaped ring and the central cells (cc). (G) Stage 3. Detail of central cells with partially degraded walls. (H) Stage 4. Central cells completely desintegrated. Scale bars: (A) =500 μm; (B) =30 μm; (C, D, F) =100 μm; (E) =20 μm (G) =1 μm; (H) =10 μm.