Flower morphology, nectar features, and hummingbird visitation to Palicourea crocea (Rubiaceae) in the Upper Paraná River floodplain, Brazil

Abstract

We investigated flower morphology, nectar features, and hummingbird visitation to Palicourea crocea (Rubiaceae), a common ornithophilous shrub found in the riparian forest understory in the Upper Paraná River floodplain, Brazil. Flowers are distylous and the style-stamen dimorphism is accompanied by other intermorph dimorphisms in corolla length, anther length, and stigma lobe length and form. We did not observe strict reciprocity in the positioning of stigma and anthers between floral morphs. Flowering occurr…