Convergent evolutionary patterns of heterostyly across angiosperms support the pollination-precision hypothesis

Violeta Simón-Porcar, Marcial Escudero, Rocío Santos-Gally, Hervé Sauquet, Jürg Schönenberger, Steven D. Johnson, Juan Arroyo

Since the insights by Charles Darwin, heterostyly, a floral polymorphism with morphs bearing stigmas and anthers at reciprocal heights, has become a model system for the study of natural selection. Based on his archetypal heterostylous flower, including regular symmetry, few stamens and a tube, Darwin hypothesised that heterostyly evolved to promote outcrossing through efficient pollen transfer between morphs involving different areas of a pollinator’s body, thus proposing his seminal pollination-precision hypothesis. Here we update the number of heterostylous and other style-length polymorphic taxa to 247 genera belonging to 34 families, notably expanding known cases by 20%. Using phylogenetic and comparative analyses across the angiosperms, we show numerous independent origins of style-length polymorphism associated with actinomorphic, tubular flowers with a low number of sex organs, stamens fused to the corolla, and pollination by long-tongued insects. These associations provide support for the Darwinian pollination-precision hypothesis as a basis for convergent evolution of heterostyly across angiosperms.

Department of Botany and Biodiversity Research
External organisation(s)
Universidad de Sevilla, Universidad Nacional Autonoma de Mexico, National Herbarium of New South Wales, University of KwaZulu-Natal
Nature Communications
No. of pages
Publication date
Peer reviewed
Austrian Fields of Science 2012
106008 Botany, 106012 Evolutionary research, 106042 Systematic botany
ASJC Scopus subject areas
Physics and Astronomy(all), Chemistry(all), Biochemistry, Genetics and Molecular Biology(all)
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