Scanning electron micrographs of Orvibestus cinerascens (Sch. Bip. in Schweinf.) H. Rob. A Polar view showing 3 colpi B Polar view showing 4 colpi C Lateral view showing highly perforated sheet-like layers of exine common in many grains of the sample D Equatorial view (appearing nearly echinolophate) E Lateral/equatorial view showing 2 pores F Fractured grain showing thickened columellae supporting a higher perforate surface G Fractured polar surface (A–GKoekemoer 232).