A PALYNOTAXONOMIC STUDY OF THE GENUS TROLLIUS (RANUNCULACEAE)

Pollen of 29 Trollius species was investigated with light and scanning electron microscopy. The grains are suboblate to prolate, circular in outline in polar view, (2)3(5)-colpate, striate or striato-rugulate. Three pollen types are recongnised: (1) T acaulis-type including T. acaulis, T. lilacinus, T. afghanicus, T. chartosepalus, and T. laxus is characterized by a roughly striate or striato-rugulate surface, granulate colpus membranes. and generally larger grain size, (2) T. chosenensis-type including only this species is characterized by a roughly striate surface, gemmate colpus membranes, and large grain size; and (3) T. europaeus-type including most of the species is characterized by a finely striate surface, shortly echinate colpus membrane, and generally smaller grains. The sectional system of Doroszewska (1974) is compared with the groups suggested by the palynological results and it is proposed that it should be amended.