XVI International Botanical Congess

Phylogenetic analyses using matK and ITS sequence data were conducted to assess the monophyly of Gronovioideae and their relationship to other Loasaceae. The monophyly of Gronovioideae and their placement as the sister clade of Mentzelia was strongly supported. Gronovioideae has two major clades: 1) Petalonyx and 2) Cevallia, Fuertesia and Gronovia. Gronovioids have simpler flowers than other Loasaceae, especially in regard to their haplostemony and uniovulate gynoecium, but their flowers have various novelties centered in stamen and petal forms. To understand morphological diversification we have mapped gronovioid floral ontogenies on our molecular based phylogenetic hypotheses.