Systematics Section / ASPT
Williams, Kyle , Kress, W. John , Larsen, Kai .
A Preliminary Molecular Phylogenetic Analysis of Caulokaempferia (Zingiberaceae): How Many Genera?.
Caulokaempferia K. Larsen is a small (ca. 12 spp.) and unusual genus of gingers (Zingiberaceae) from Southeast Asia. All species are small herbs that are almost exclusively found growing on moist, exposed rocky substrates. The species of this genus fall into two distinctive morphological groups. One group consists of white to pink-flowered taxa 10-30 (-50) cm tall that generally grow in a shallow humus layer on top of exposed rock. The other group contains (usually) yellow-flowered species that are smaller in stature (generally less than 10 cm) and grow in rocky, vertical stream banks. In addition, an unusual yellow-flowered species, C. yunnanensis, was previously segregated as the monospecific Pyrgophyllum. The family-wide molecular phylogenetic analysis of Kress et al. (2002) placed Caulokaempferia within subfamily Zingiberoideae, but failed to resolve its tribal placement (i.e. Globbeae or Zingibereae). However, only yellow-flowered species were sampled for that analysis. A molecular analysis of Caulokaempferia has been initiated in order to examine relationships within the genus and to further resolve the position of Caulokaempferia within the Zingiberaceae. Preliminary results using the nuclear ITS spacer and chloroplast trnK-matK regions demonstrate that Caulokaempferia as currently circumscribed is polyphyletic, with the white-flowered species showing a close relationship to Boesenbergia. Morphological characters differentiating the two clades of Caulokaempferia and linking the white-flowered group to Boesenbergia will be discussed. Future study will focus on increased sampling of Boesenbergia species to further elucidate its relationship to the white-flowered group of Caulokaempferia. Sequencing of additional regions of DNA will also be conducted in order to attempt to place the yellow-flowered group of species to tribe. These results suggest that the Zingiberaceae classification of Kress et al. (2002) will be further refined to reflect a modern understanding of relationships within the gingers.
1 - University of Aarhus, Department of Systematic Botany, Institute of Biology, Nordlandsvej 68 DK-8240, Risskov, , Denmark
2 - Harvard University, Arnold Arboretum, 22 Divinity Avenue, Cambridge, Massachusetts, 02138, USA
3 - Smithsonian Institution, Department of Botany, MRC166, National Museum of Natural History, P.O. Box 37012, Washington, DC, 20013-7012, USA
Presentation Type: Paper
Location: Cottonwood B (Snowbird Center)
Date: Monday, August 2nd, 2004
Time: 5:15 PM