Evolution of the South African Bruniaceae

Bruniaceae are a small family subendemic to the Cape Floristic Region (one species in Natal). Species grow as sklerophyllous shrubs or small trees and are often restricted to mesic habitats at higher altitudes. Many of them are only locally known from single populations. Being one of the few endemic South African families, Bruniaceae play an important role in reconstructing the evolution of the Cape Flora.

When we started the project on Bruniaceae, little was known about the biology and evolution of the lineage. We first investigated plant and inflorescence architecture and then continued with flower morphology, pollination ecology and phylogeny. Bruniaceae are adapted to the Mediterranean climate with small everlasting leaves and a not seasonally fixed growth rhythm. Flowers are usually arranged in globular clusters, present nectar at the base of the ovary and are pollinated by flies, beetles and other unspecialized insects. Both protandry and protogyny occur increasing outcrossing. Based on molecular data, we reconstructed the evolutionary history of the family. Bruniaceae appear as an ancient relict family, which mainly diversified with the climatic change at the Miocene-Pliocene boundary. Combining morphological and morphological data, we proposed a new classification of the family including three tribes, six genera and 81 species.

The project was financially supported by the Deutsche Forschungsgemeinschaft (DFG Cl 81/4-1/2, Cl 81/8-1/2, Cl 81/12-1/2) and ended in 2010. At present, we are reevaluating the inflorescence structure of some species connecting the family to our interest in `inflorescence development´.

Publications

Claßen-Bockhoff R. 1994: Verzweigungsverhalten und Infloreszenzstruktur der Bruniaceen: systematische, morphologische und phylogenetische Schlußfolgerungen. Habilitationsschrift, Rheinisch-Westfälische Technische Hochschule Aachen.

Claßen-Bockhoff R. 1995: Wuchsverhalten und Infloreszenzstruktur in der Gattung Nebelia (Bruniaceae). Feddes Repert. 106: 415-437.

Claßen-Bockhoff R. 2000: Inflorescences in Bruniaceae. Opera Bot. Belg. 12: 5-310.

Claßen-Bockhoff R. 2016. Bruniaceae. In Kubitzky K (ed.), The Families and Genera of Vascular Pants. Vol. 14: Flowering Plants: Eudicots: 103-115.

Claßen-Bockhoff R., Oliver EGH, Hall AV., Quint M. 2011: New classification of the Bruniaceae based on molecular and morphological data. Taxon 60:1138-1155

Oliver EGH., Hall AV., Claßen-Bockhoff R. 2010. Two new species of Bruniaceae from Western Cape, South Africa. Bothalia 40: 96-101

Quint M. 2004. Evolution of Bruniaceae: evidence from molecular and morphological studies. PhD thesis, Universität Mainz.

Quint M., Claßen-Bockhoff R. 2006: Phylogeny of Bruniaceae based on matK and ITS sequence data. Int. J. Plant Sci. 167: 135-146.

Quint M., Claßen-Bockhoff R. 2006: Floral ontogeny, petal diversity and nectary uniformity in Bruniaceae. Bot. J. Linn. Soc. 150: 459-477.

Quint M., Claßen-Bockhoff R. 2008: Ancient or recent? New insights on the age of the Bruniaceae and the evolution of the Cape Flora. Organisms, Diversity and Evolution 8: 293-304.

Schardt L. 2010. Evolution of South African Bruniaceae: evidence from ecological and geographical investigations. PhD thesis, Universität Mainz.

Warren B., Bakker FT., Bellstedt DU., Bytebier B., Claßen-Bockhoff R. , Dreyer LL., Edwards D., Forest F., Galley C., Hardy CR., Linder HP., Muasya AM., Mummenhoff K., Oberlander KC., Quint M., Richardson JE., Savolainen V., Schrire BD., van der Niet T., Verboom GA., Yesson C., Hawkins JA. 2011: Consistent phonological shifts in the making of a biodiversity hotspot: the Cape flora. BMC Evolutionary Biology. http://www.biomedcentral.com/1471-2148/11/39