Systematic relevance of pollen morphology in tribe Hylocereeae (Cactaceae) Author Ruiz-Dominguez, Catalina Author Vovides, Andrew P. Author Sosa, Victoria text PhytoKeys 2019 128 121 140 http://dx.doi.org/10.3897/phytokeys.128.35842 journal article http://dx.doi.org/10.3897/phytokeys.128.35842 1314-2003-128-121 E7F6A30F8981545BB28061827C26D30E 3378137 Acanthocereus (Engelm. ex A. Berger) Britton & Rose Pollen. trizonocolpate, radially symmetrical, isopolar with circular contour in polar view. Shape : varies from subprolate to oblate-spheroidal (P/E=0.97-1.29). Apertures : 3, colpate, large; polar area of medium size (PAI=0.31-0.40). Measurements : pollen grains of large size (49.02)56.81(68.53) x (49.89)63.62(79.4) μm in equatorial view; exine thickness (2.41)3.29(4.19) μm . Ornamentation : smooth surface with tectum perforate, ornated with spinules of (1.05)1.43(1.76) μm length x (1.08)1.37(1.83) μm diameter in base; perforations (0.17)0.25(0.33) μm in diameter ( Figure 3A ). Figure 3. Pollen grains of tribe Hylocereeae (Scanning Electron Microscope photographs). Left polar view, right equatorial view A Acanthocereus tetragonus (C. Ruiz et al. 576) B Disocactus ackermanii (R. Torres et al. 309) C Epiphyllum oxypetalum (C. Ruiz et al. 640) D Selenicereus costaricensis (C. Ruiz et al. 555) E S. escuintlensis (C. Ruiz et al. 635) F S. guatemalensis (M. Veliz et al. 20227) G S. minutiflorus (C. Ruiz et al. 627) H S. ocamponis (M. Chazaro 7334) I S. polyrhizus (C. Ruiz et al. 566) J S. sp. (C. Ruiz et al. 608). Species examined. Acanthocereus tetragonus (L.) Hummelinck (Colombia, Valle del Cauca. C. Ruiz et al. 576 CUVC); Acanthocereus chiapensis Bravo ( Mexico , Chiapas. C. Gomez-Hinostrosa et al. 2325 MEXU).