Abstract
The epidermal microcharacters of 20 genera in the Ranunculaceae and 10 outgroup genera from the families Glaucidiaceae, Circaeasteraceae, Berberidaceae, Menispermaceae, and Lar- dizabalaceae were studied employing scanning electron and light microscopy. Characters such as type of trichome and stomatal length are valuable tools in assessing phylogeny in the Ranunculaceae. Using cladistic analyses, the basic division of the family into two major groups according to chro- mosome size (R- and T-types) was confirmed. By outgroup polarization, the T-type chromosome group is considered most primitive. Two major clades are recognized in the T-type taxa: the Aquilegia and Thalictrum group including closely related genera and a group consisting of Coptis and Xan- thorhiza. Hydrastis is not consjdered a member of the Ranunculaceae. Further cladistic analyses of the R-type taxa using macrocharacters derived mainly from floral and fruit morphology resulted in the following subdivisions: the Anemone and Ranunculus group including Pulsatilla, Hepatica, and Clematis; the Cimicifuga and Actaea group; and the Helleborus group including Eranthis, Trollius, and Caltha. The Ranunculaceae, a large and varied fam- ily, consist of approximately 66 genera and 2000 species (Takhtajan 1987). Members of the family are distributed throughout the world, but are centered in the temperate and cold regions of both hemispheres; representatives are uncom- mon in tropical and subtropical zones except in montane regions (Ziman and Keener 1989).
Published Version
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