Figure 9 from: De Block P, Rakotonasolo F, Ntore S, Razafimandimbison SG, Janssens S (2018) Four new endemic genera of Rubiaceae (Pavetteae) from Madagascar represent multiple radiations into drylands. PhytoKeys 99: 1-66. https://doi.org/10.3897/phytokeys.99.23713

Figure 9 Pollen of Exallosperma and Helictosperma. A–D, M Exallosperma longiflora E–H, N Helictosperma malacophylla I–L H. poissoniana. A, E, I polar view B, F, J equatorial view C, G, K mesocolpium D, H, L ectoaperture M, N pollen grain wall. A, M Nusbaumer & Ranirison 1992 B–D De Block et al. 1132 E–H, N Phillipson 3068 I–L Leandri 573.