Systematics, biogeography, and ethnobotany of the pantropical family Cochlospermaceae (Malvales).

摘要

This dissertation reports on the molecular systematics, biogeography, and ethnobotany of the pantropical plant family, Cochlospermaceae. The goal was to examine its origin, diversification, and evolution of morphology. Ethnobotanical data were also reviewed and compared across species and geographic regions, in light of phylogeny, to explore similar use patterns. The data support the monophyly of Cochlospermaceae and its distinctiveness from its allied families, Bixaceae, Diegodendraceae, and Sphaerosepalaceae. Amoreuxia is monophyletic and is supported by an herbaceous growth form and dimorphic stamens. However Cochlospermum is paraphyletic with two South American species, C. orinocense and C. tetraporum , that occur as separate basal lineages. Morphological character states that appear to be ancestral for the family include an arborescent habit, radially symmetrical flowers, and anthers with two apical pores. Biogeographic analyses support a late Cretaceous origin for the family in South America and subsequent dispersals into Central and North America, the West Indies, Africa, Australia, and Southeast Asia through a combination of long distance dispersal, vicariance, and human introduction. Divergence time estimates using fossil calibrations support dispersal from South America across Antarctica during the Late Paleocene Thermal Maximum and the Early Eocene Climatic Optimum before South America and Australia separated from Antarctica. Ethnobotanical research uncovered Cochlospermaceae to be an ethnobotanically rich family, with diverse uses spanning its pantropical distribution. Many species of Cochlospermaceae are used in similar ways in different geographic regions among diverse cultures. These uses range from food to fiber to medicine, with most of the human uses being medicinal. The most common medicinal uses are treating skin ailments, gastro-intestinal problems, malaria, and liver issues, with C. tinctorium having the most medicinal uses. Closely related species used by cultural groups in different regions to treat the same illnesses, suggests the presence of active compounds with potential biomedical value, since they may represent independent discoveries of similar medicinally-active compounds.