In Utricularia, the flower spur is a nectary and in this organ, nectar is produced and stored. This study aimed to examine the structure of the nectary trichomes in four Utricularia species (Utricularia vulgaris L., U. australis R.Br., U. bremii Heer and U. foliosa L.) from the generic section Utricularia. We have investigated whether species with different spur morphology had similar spur anatomy and nectary trichome structure. In Utricularia flowers, nectar is produced by spur capitate trichomes (sessile or stalked). Our results showed that regardless of the various spur morphology, trichomes have similar architecture and ultrastructure. Head cells of these trichomes are transfer cells with an eccrine nectar secretion. Examined species differed in the micromorphology of papillae in spurs. The fly Eristalis tenax was found to be a pollinator of U. vulgaris. Small Halictidae bees seem to be pollinators of U. foliosa.

Botanic Garden Faculty of Biology University of Warsaw Al Ujazdowskie 4 00 478 Warsaw Poland

Department of Animal Histology and Embryology University of Silesia in Katowice 9 Bankowa St 40 007 Katowice Poland

Department of Plant Cytology and Embryology Jagiellonian University in Kraków 9 Gronostajowa St 30 387 Cracow Poland

Faculdade de Ciências Agrárias e Veterinárias Jaboticabal Departamento de Biologia Aplicada à Agropecuária Universidade Estadual Paulista São Paulo Brazil

Section of Plant Ecology Institute of Botany of the Czech Academy of Sciences Dukelská 135 37982 Třeboň CZ Czech Republic

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