Abstracts of Posters


Phylogeny and character evolution
of the Catesbaeeae-Chiococceae complex (Rubiaceae).

Piero G. Delprete
Institute of Systematic Botany, The New York Botanical Garden, Bronx, NY 10458-5126, U.S.A.
E-mail: pdelprete@nybg.org
& Timothy Motley
Lewis B. & Dorothy Cullman Program for Molecular Systematics Studies,
The New York Botanical Garden, Bronx, NY 10458-5126, U.S.A. E-mail: tmotley@nybg.org.

The classification of the Catesbaeeae and Chiococceae (two tribes well represented in the Greater Antilles), along with the entire Rubiaceae, has been intensely debated in recent years. This debate has focused on a few key morphological characters (corolla shape and aestivation, anther shape and position, fruit placentation, and number and position of ovules) and one set of molecular data (rbcL). Several recent phylogenetic analyses in the Rubiaceae based on nucleotide sequences of the trnL-F and rps16 regions of the plastid genome and the nuclear ribosomal internal transcribed spacers (ITS1&2) suggest that none of the previously proposed classifications are entirely correct, and that the Catesbaeeae (including the Portlandia group), characterized by large flowers and multi-seeded fruits with dry of fleshy mesocarp, and the Chiococceae, characterized by small flowers and 2-seeded (6-8-seeded in Erithalis) fruits with fleshy or dry mesocarp, form a strongly-supported monophyletic group. New data suggest that the traditionally defining flower and fruit features of the Catesbaeeae and Chiococceae are actually phylogenetically homoplastic, leaving present generic boundaries and relationships within the Catesbaeeae-Chiococceae-complex in doubt. The evolution of the these cardinal morphological characters were investigated using a combination of molecular, morphological, anatomical and palynological data.