PHYLOGENETIC ANALYSIS OF IRIDACEAE WITH PARSIMONY AND DISTANCE METHODS USING THE PLASTID GENE RPS4

A molecular phylogeny of the family Iridaceae based on the plastid gen e rps4 was obtained using both parsimony and distance methods. Thirty- four species were examined together with eight outgroup species. Resul ts show that the Iridaceae are monophyletic, and that Isophysis is lik ely to be the earliest emerging genus. Subfamily Ixioideae plus the ge nera Aristea and Nivenia form a strongly supported clade. Within subfa m. Iridoideae, the tribe Irideae includes the genus Bobartia (of dispu ted position), and the tribe Mariceae includes Cypella. The division o f Iridoideae into tribes is consistent with their geographical distrib ution.