Scanning electron micrographs of Vernonella and Vernoniastrum. A–C Scanning electron micrographs of acetolyzed sublophate-echinolophate pollen of Vernonella africana Sond. A Polar view B Equatorial view C Oblique polar view. A–C from Wood 753. D–I Scanning electron micrographs of acetolyzed echinolophate pollen of Vernoniastrum nestor (S. Moore) H. Rob., showing diversity of lacunae and lophae. D–H Oblique and near polar views showing apertures in markedly long lacunae with irregular lophae H Lateral view with apertures (arrows) occupying long lacunar spaces I Enlarged section of surface showing columellae in irregular rows under muri). D–I from Reekmans 9185.