Abstract
Pollen morphology of Nymphaea lotus L. (Nymphaeaceae) was described by light and scanning electron microscopy. Pollen grains extracted from different types of stamens (including petaloid ones) of N. lotus exhibited a wide range of pollen morphological variation in form, size, aperture, and sculpture. Special emphasis was given to the presence of the primitive monocotyledonoid aperture type referred to as ‘zonisulculate’. The significance of this aperture type in delimiting the phylogeny of the family was discussed. The family Nymphaeaceae was compared with other dicotyledonous (Eupomatiaceae and Monimiaceae) and monocotyledonous families (Araceae, Arecaceae, Liliaceae, Philydraceae, Rapateaceae, and Xanthorrhoeaceae) possessing zonisulculate pollen grains. No direct relationships were considered to exist between Nymphaeaceae and these families when the present pollen morphological study was combined with other morphological characters as revealed by previous taxonomic treatments.
