KNOX, ERIC B.1* and A. MUTHAMA MUASYA2. 1Department of Biological Sciences, Rutgers University, Newark, NJ 07102; 2East African Herbarium, National Museums of Kenya, Nairobi, Kenya. - The phylogeny and biogeography of the Lobeliaceae based on the chloroplast genes atpB and rbcL and their intergenic spacer sequence.
The emerging phylogenetic estimate for the Lobeliaceae based on
chloroplast DNA sequence variation shows strong phylogenetic and
biogeographic patterns. Lobelia is the ‘core genus’ of the
family, from which the remaining genera in the family have evolved.
Twenty of the 30 segregate genera have been surveyed to-date. In most
cases, these segregate genera are closely related to Lobelia
species from the same geographic area in which the segregate genus
occurs. These strong biogeographic affinities are also observed within
Lobelia, with a few notable exceptions. The Lobeliaceae
originated in southern Africa, and relatively few long-distance
dispersal events are needed to account for their almost cosmopolitan,
contemporary distribution. However, part of the taxonomic diversity in
Australasia is due to repeated introductions, and the pantropical
distribution of the giant lobelias is due to successive dispersal
Key words: Africa, biogeography, chloroplast DNA, Lobelia, Lobeliaceae, phylogeny