Meeting Abstract

P3.87  Sunday, Jan. 6  Morphological evolution within Miconieae (Melastomataceae): Insights from the Secundiflorae clade using morphometric data AUGUSTIRO, W.*; OCAMPO, G.; University of Hawaii, Manoa; California Academy of Sciences, San Francisco, California wendeea@hawaii.edu

The Melastomataceae is a large tropical to subtropical family with ca. 5000 species. One of its tribes, Miconieae, includes about 2200 species distributed exclusively in the Neotropics. Within Miconieae, generic circumscription has been problematic and molecular phylogenetic studies have shown that the genera are not monophyletic, suggesting that some characters used for circumscribing the genera are homoplastic. One of the retrieved clades, known as the Secundiflorae clade, has species that are morphologically similar, and the sizes of vegetative and reproductive characters overlap. To study size variation amongst the species of the Secundiflorae clade, DNA and morphometric data were analyzed for 12 taxa. Phylogenetic analyses of nuclear and chloroplast markers showed that the clade is strongly supported as monophyletic. Statistical analyses indicated that the species could not be separated out by morphometric data alone, which suggests a significant degree of overlapping values among species; therefore, morphometric data may not be helpful for segregating species along their entire distribution range. Comparative analyses showed that the morphometric data has no phylogenetic signal, but there is a positive correlation between adaxial leaf hair length and elevation, which suggests that some morphometric variation may have an adaptive component rather than a phylogenetic one. Additional taxa and traits may help to understand the variation within the Secundiflorae clade, which might, at the same time, be a reference for studying the morphological evolution in the highly diverse tribe Miconieae.