XVI International Botanical Congess

Aralia and Panax are two closely related genera of Araliaceae. Morphological characters and the sequences of the internal transcribed spacer regions of nuclear ribosomal DNA and the chloroplast gene ndhF were employed to construct the phylogeny of Aralia and Panax. Congruent results were obtained from the ITS and the ndhF datasets. Panax, the ginseng genus, is nested within Aralia. The New World Aralia sect. Humiles is phylogenetically basal within the Aralia - Panax complex. The morphologically isolated North American Aralia hispida belongs to Aralia sect. Dimorphanthus. Herbaceous habit evolved at least three times within the Aralia - Panax complex. Morphological stasis is supported for some eastern Asian and eastern North American disjunct taxa within the complex.