The systematic value of pollen morphology in Operculina (Convolvulaceae)

Abstract

Operculina is a pantropical genus of 14 species, perhaps one of the most stable in taxonomic delimitation in Convolvulaceae. Its operculate-capsular fruit is distinctive and unique in the family, and shared by all species it comprises, despite great variation in other macromorphological traits. Recent molecular phylogenetic results have demonstrated Operculina is monophyletic with high support, re-enforcing the generic concept. However, revisionary studies of its taxonomy and morphology are limited, and information about its species is mostly scattered in regional works. Particularly in palynology, there are few studies that have included this genus, and usually only the most common species O. turpethum. Here, we provide an overview of the palynological diversity in 12 Operculina species and discuss the evolution and taxonomic relevance of aperture heteromorphism in this genus.

Keywords:

• Operculina
• tricolpate
• heteromorphism

Acknowledgements

The authors would like to thank Fundação Ciência e Tecnologia Grant SFRH/BD/45924/2008 (2009–2013) for funding of Ana R. Simões’s PhD project, under which the palynological analyses were conducted.; also, Brazilian CAPES – BJT Grant 88881.067993/2014-01 (2015–present) for allowing the preparation of this manuscript; Dr Mark Carine (Natural History Museum of London) for the supervision of Simões’ PhD studies; Dr Hannah Banks (Jodrel Laboratory, Kew) for having helped with the palynological analyses in this study, and feedback on the manuscript; all staff at Kew Jodrel Laboratory Micromorphology Laboratory; also Dr Rosangela Simão-Bianchini (Instituto de Botânica – São Paulo, Brazil), Dr George Staples (Harvard University Herbaria), Dr Maria Teresa Buril (Universidade Federal Rural de Pernambuco, Brazil) and MSc Fernanda Satori Petrongari (Instituto de Botânica – São Paulo, Brazil) for useful scientific discussions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Fundação para a Ciência e a TecnologiaGrant SFRH/BD/45924/2008 (2009–2013)and Coordenação de Aperfeiçoa-mento de Pessoal de Nível Superior (CAPES) - Bolsa Jovens Talentos 88881.067993/2014-01 (2015–2018).