Pollen morphology of Cyclanthera and Sicyos species (Cucurbitaceae, Sicyoeae)

pollen morphology of eight species of cyclanthera and three species of sicyos was studied using light and scanning electron microscopy. pollen grains of cyclanthera have a mean polar diameter of 51.40 μm, and an equatorial mean diameter of 49.10 μm, a prolate spheroidal shape (p/e = 1.11), 4-7 zonocolporate, with circular endoapertures, and punctitegilate exine. pollen grains of sicyos have a mean polar diameter of 50.60 μm and a mean equatorial diameter of 61.30 μm, an oblate spheroidal shape (p/e = 0.88), 8-12 colpate, supra and microreticulate echinate exine. differences among the genera and species are discussed.