FRASIER, CYNTHIA L.1*, VICTOR A. ALBERT2 and LENA STRUWE1,3. 1Dept. of Plant Biology, 273 Foran Hall, 59 Dudley Road, Rutgers University, Cook College, New Brunswick, NJ; 2The Natural History Museums and Botanical Garden, University of Oslo, Sars' gate 1, N-0562 Oslo, Norway; 3Dept. of Ecology, Evolution, and Natural Resources, 237 Foran Hall, 59 Dudley Road, Rutgers University, Cook College, New Brunswick, NJ. - Comparison of biogeographic and phylogenetic patterns in a medicinally important gentian genus in Latin America (Potalia; Gentianaceae-Potalieae).
In the neotropical lowlands of the Amazon, Potalia grows as an
under-story shrub or small tree. Indigenous people frequently use
these phytochemically potent plants against malaria, fungal diseases,
fevers, inflammations, and animal bites. Potalia (with ca. 9
species) is a monophyletic genus that shows primarily allopatric
(non-overlapping) species distributions. Three species have
non-Amazonian distributions - one in Panama and Costa Rica and two in
Chocó, Colombia. Several Amazonian species are endemic to restricted
areas and occur nearly exclusively in nutrient-poor, white-sand
savannas or caatingas. Phylogenetic and biogeographic patterns were
analyzed using cladistic methods and molecular (ITS and 5S-NTS) and
morphological data. Preliminary analyses indicate an ancestral
distribution of Potalia on the relatively older white-sand
areas, with subsequent dispersal to younger sediments and soil types.
Hypotheses of detailed speciation patterns in Potalia and
biogeographic patterns of Amazonia and other areas in Latin America
will be presented and evaluated.
Key words: biogeography, ethnobotany, evolution, Gentianaceae, molecular systematics, morphology