Abstract: The present paper deals with the pollen morphology of 103 species belonging to six
genera-Castanea, Castanopsis, Lithocarpus, Quercus, Fagus and Trigonobalanus in three
subfamilies-Castaneoideae, Quercoideae and Fagoideae. All pollen grains were examined
under light microscope and scanning electron microscope, and those of some species were ex-
amined under transmission electron microscope. The results may be summarised as follows:
1. Pollen morphology of Fagaceae, seems to support division of the family into three
subfamilies. Fagoideae, Castaneoideae and Quercoideae.
2. Four types of pollen grains are recognized in Fagaceae:
1) Fagus-type (representative genus: Fagus): pollen granis are oblate-sphaeroidal,
(31.5-39.9) x (35.7 46.2) μm in size, 3(-4)-colporate, peritreme or goniotreme, granulate-
ornate under LM., granulate or verrucate under SEM.
2) Trigonobalanus-type (T. doichangensis): pollen grains are suboblate-sphaeroidal,
(23.1-29.4) ×(25.2-29.4) μm in size, 3-colporate, goniotreme, obscurely granulate-ornate
under LM, densely granulate or verrucate under SEM.
3) Quercus-type (Quercus): pollen grains are subspheroidal-subprolate, (21-44.3)
× (16.8-39.9) μm in size. 3-colporoidate (-3-colpate), peritreme, crassgranulate or finely-gra-
nulate under LM, tuberculate verrucate or spinate under SEM.
4) Castanea-type (including Castanea, Castanopsis, Lithocarpus): Pollen grains are
prolate-supraprolate, (14.7-23.1)×(10.5-16.8)μm in size; 3-colporate, peritreme, obscu-
rely ornate or subpsilate, under LM, rugulose, striate-rugulate or crass-striate under SEM.
3. Pollen grains of Cyclobalanopsis age very similar to those of Quercus, and there-
fore we support the treatment of Cyclobalanopsis as a subgenus of Quercus.
4. On the basis of shape, type of aperture and exine structure, pollen of Trigonobalanus
is distinguishable from those of the other genera in Fagaceae and it may be a new type of Fagaceae;
5. On the basis of pollen morphology, morphological characters and geological stratification a scheme of phylogeny of Fagaceae is here presented.

Key words: Fagaceae, Pollen morphology, Ultrastructure, Phylogeny