PHYLOGENY AND FRUIT EVOLUTION IN MENISPERMACEAE

Premise of the study: This work surveys endocarp morphology of Menispermaceae in the context of a well-supported molecular phylogeny. The study is important since menispermaceous endocarps appear often in the fossil record and indicate the presence of a wet forest ecosystem. Methods: Three chloroplast regions were used to derive phylogenies for 53 genera and 60 species. Endocarps of 47 genera and 92 species were dissected and morphological characters scored. Photographs of key features are presented. We superimposed our morphological matrix onto the phylogeny to explore character evolution. A detailed key to fruits is presented, allowing identification of extant and fossil specimens to the level of clade or genus. Key results: Menispermaceae consists of two major subfamilies: Tinosporoideae and Menispermoideae. Within Tinosporoideae, tribe Coscineae is basal. Within Menispermoideae, tribe Menispermeae is basal. Tinosporoideae consists mainly of taxa with apical style scars, bilateral curvature, subhemispherical condyles, and foliaceous cotyledons with divaricate or imbricate orientation. Menispermoideae consists almost entirely of taxa with basal or subbasal style scars, dorsoventral curvature, bilaterally and/or dorsoventrally compressed condyles, and subterete or fleshy cotyledons oriented dorsoventrally or laterally. Conclusions: Several fruit characters differentiate major clades, and further synapomorphies are diagnostic of various sub-clades. Fruit characters that can be inferred as ancestral in the family are basal or subbasal stylar scars, endocarps with dorsoventral curvature, endocarp walls woody or bony, presence of a condyle, locule without ribs, sublateral vascular traces, presence of endosperm, and foliaceous or subterete cotyledons.