Abstract: The present paper describes the pollen morphology of 11 species of thc genus Corylopsis (Hamamelidaceae). The pollen grains were all examined with light microscope and scanning electron microscope. Pollen grains of the genus are prolate, spheroidal or subprolate. Three size types are recognized: (l) 18-23 μm, found in Corylopsis omeiensis Yang, C.gotoana Makino, C. himalayana Griff and C.platypetala Rehd. et Wils. (2) 24-32μm, found in C. sinensis Hemsl., C.willmottiae Rehd. et Wils., C.veitchiana Bean, C. brevistyla H.T.Chang, C.multiflora Hance, C.pauciflora Sieb. et Zucc. and C.spicata Sieb. Zucc. (3) 34-39μm, found in C. wilsonii Hemsl. and C. cordata Merrill. Pollen grains are 3-colpate and 4-colpate (only infrequently found in Corylopsis sinensis Hemsl.); the exine is 2-layered, 1.25-2.50μm thick, distinctly reticulate, sexine almost equal to nexine in thickness. From the pollen morphology the genus is considered as a natu-ral group.

Key words: Pollen morphology, Corylopsis, Hamamelidaceae