SEM micrographs of pollen grains of Clerodendrum A–C C. chinense D–F C. villosum G–I C. trichotomum J–L C. mandarinorum M–O C. lindleyi P–R C. colebrookianum. Equatorial view: A, D, G, J, M, P; polar view: B, E, H, K, N, Q; exine ornamentation: C, F, I, L, O, R. Scale bars: 10 μm (A, B, D, E, G, H, J, K, M, N, P, Q); 3 μm (C, F, I, L, O, R).