A RESOLUTION OF THE EUGENIA–SYZYGIUM CONTROVERSY (MYRTACEAE)

Abstract

Floral anatomy now provides additional, strong evidence confirming the distinctness of the mainly New World Eugenia s. s . and the strictly Old World Syzygium s. l . Most significantly, species of Eugenia s. s . have a transeptal vascular supply to the ovules whereas those of Syzygium s. l . have an axile one. Other features of floral histology and vasculature also support such a division. In addition, a review of the taxonomic literature revealed three hitherto neglected organographic criteria—nature of bracteoles, presence or absence of pubescence, and presence or absence of pseudopedicels—that sharply distinguish between Eugenia s. s . and Syzygium s. l . An ensemble of these and other organographic criteria further demonstrates the basic disparity of these taxa. The organography and histology of flowers of Eugenia s. l . are described in detail, with .26 characters contrasting the Old and New World species included in a table.