A reassessment of the familial affinity of the Mexican genus Recchia Mocino & Sesse ex DC

Sequence data for the rbcL locus were obtained for two of the three species of the Mexican endemic Recchia. Parsimony analyses of the molecular data base indicate that Surianaceae sensu Cronquist are paraphyletic; inclusion of Recchia rendered the family monophyletic. This placement is corroborated by a suite of morphological characters: an apocarpous (or monocarpic) gynoecium of bi-ovulate carpels with basal-marginal placentation and a ventrobasal style, and the occurrence in all but Guilfoylia of a characteristic 3-layered endocarp. The molecular data support a closer relationship between Recchia and the Australian Cadellia than between the latter and any of the other Australian genera. The molecular data suggest that the affinities of Surianaceae lie in a clade comprising at least Polygalaceae, Fabaceae, and Quillaja.