Selenicereus (Hylocereus sect. Hylocereus clade)

Pollen.

trizonocolpate, radially symmetrical, isopolar with circular contour in polar view. Shape: varies from suboblate to subprolate (P/E=0.86-1.18). Apertures: 3, colpate (brevicolpate in S. minutiflorus), large (small in S. minutiflorus); polar area medium-sized to large (PAI=0.30-0.59). Measurements: pollen grains of medium to very large size, (54.52)78.67(97.83) × (45.94)83.68(102.53) μm in equatorial view; exine thickness (1.66)2.95(4.10) μm . Ornamentation: smooth surface with tectum perforate, ornated with spinules ( S. minutiflorus and S. stenopterus without spinules) of (1.06)1.47(2.13) μm length × (0.72)1.23(1.53) μm diameter in base; perforations (0.20)0.39(0.89) μm in diameter (Figures 3D, 3E, 3F, 3G, 3I, 3J, 4A, 4E, 4F).

Species examined.

Selenicereus costaricensis (F.A.C. Weber) Britton & Rose (Colombia, Valle del Cauca. C. Ruiz et al. 555 CUVC); S. escuintlensis Kimnach (Guatemala, Escuintla. C. Ruiz et al. 635 BIGU); S. guatemalensis (Eichlam ex Weing.) Britton & Rose (Guatemala, El Progreso. M. Véliz et al. 20227 BIGU); S. minutiflorus Britton & Rose (Guatemala, Izabal. C. Ruiz et al. 627 BIGU); S. monacanthus (Lemaire) Britton & Rose (Honduras, Francisco Morazán . C. Ruiz et al. 493 TEFH); S. polyrhizus (F.A.C. Weber) Britton & Rose (Colombia, Valle del Cauca. C. Ruiz et al. 566 CUVC); Selenicereus sp. ( México, Oaxaca. C. Ruiz et al. 608 XAL); S. stenopterus (F.A.C. Weber) Britton & Rose (Costa Rica, Alajuela. C.K. Horich s.n. MEXU); S. triangularis (L.) Britton & Rose ( México, Yucatán . C. Gómez-Hinostrosa 2110 MEXU); S. undatus (Haworth) Britton & Rose (Colombia, Valle del Cauca. C. Ruiz et al. 560 CUVC).