Phylogeny of Labiatae and Verbenaceae Inferred from rbcL Sequences

Parsimony analysis of rbcL sequences supports monophyly of the Labiatae s.l., which includes the Labiatae, subfamilies Caryopteridoideae, Chloanthoideae, and Viticoideae of the Verbenaceae, and Symphoremataceae. Representatives of subfamily Verbenoideae (Verbenaceae s. str.) do not form a monophyletic group with the Labiatae s.l. Avicennia (Avicenniaceae), Cyclocheilon (Nesogenaceae), and Euthystachys and Retzia (Stilbaceae), included in the Verbenaceae by many authors, are distinct from the Labiatae s.l. and Verbenaceae s. str. The inferred phylogeny also provides a framework to interpret character evolution. Results suggest that uniovulate locules have evolved in at least two lineages of Lamiales s.l. and that a gynoecium with four locules by the development of false partitions apparently has evolved independently in the Labiatae s.l. and the Verbenaceae s. str. Whereas a dry fruit is pleisiomorphic in the Lamiales s.l., a fleshy fruit is pleisiomorphic in the Labiatae s.l. with possible reversal in four lineages.