Evolution of flowers and inflorescences in Leguminosae
Legume flowers and inflorescences are investigated in a broad ecological context, with a focus on systematic relationships and on floral function.
With c. 19,500 species, Leguminosae is among the three largest plant families. They include many species of considerable economic importance, such as pea (Pisum sativum), peanut (Arachis hypogaea) and common bean (Phaseolus vulgaris). Leguminosae show a broad range of flower and inflorescence morphologies, with relatively stable floral structure in the subfamilies Mimosoideae (mainly brush blossoms) and Papilionoideae (mainly flag blossoms) and high variability in the polyphyletic subfamily Caesalpinioideae.
Our main focus in this project, started in 2007, is to evaluate character homologies across the family and to compare traits in floral ontogeny (such as the timing of organogeny or the loss versus suppression of organs) across the family. Techniques applied include scanning electron microscopy (SEM) and light microscopy (LM). For example, a current PhD project, co-supervised at Kew, analyses the floral morphology and development of selected taxa of the early diverging caesalpinioid clade Dialiinae. An ongoing comparative study of multicarpellate legumes aims to elucidate the evolution of the mainly unicarpellate legume flower. In a collaborative project, we are studying flower evolution in the detarioid legumes to better understand character development and to help resolve the intergeneric relationships in this highly complex basally branching legume clade.
Our studies contribute to a better understanding of (1) relationships among legume taxa and (2) the systematic placement of Leguminosae within the order Fabales. Detailed data on comparative floral and inflorescence morphology are the foundation for understanding these reproductive structures in an ecological context, including the pollinating agents and reproductive systems.
Key publications 2007-2011
- Prenner, G. & Klitgaard, B.B. (2008). Towards unlocking the deep nodes of the Leguminosae: Floral development and morphology of the enigmatic Duparquetia orchidacea (Leguminosae – Caesalpinioideae). American Journal of Botany 95: 1349–1365.
- Prenner, G., Vergara-Silva, F. & Rudall, P.J. (2009). The key role of morphology in modelling inflorescence architecture. Trends in Plant Science 14: 302–309.
- Prenner, G., Bateman, R.M., Rudall, P.J. (2010). Floral formulae updated for routine inclusion in formal taxonomic descriptions. Taxon 59: 241–250.
- Prenner, G. (2011). Floral ontogeny of Acacia celastrifolia: an enigmatic mimosoid legume with pronounced polyandry and multiple carpels. Chapter 11 in Wanntorp L. & Ronse De Craene, L. (eds) Flowers on the tree of life: Cambridge, UK: Cambridge University Press.
Project partners and collaborators
Anne Bruneau, Erin Zimmerman, Institut de Recherche en Biologie Végétale, Université de Montréal, Canada.
Simone de Pádua Teixeira, Juliana Villela Paulino, Departmento de Ciências Farmacêuticas de Ribeirão Preto, Universidade de Sao Paulo (USP), Brazil.
Shirley Tucker, Faculty of Biological Sciences, University of California, Santa Barbara
Bentham Moxon Trust, Kew core funded.