Accara

Abstract: Myrtus elegans cannot be accomodated realistically in any existing genus of the Myr- taceae. A new genus, Accara, is described to contain it; a new combination is made, Accara elegans. The relationship of Accara to its apparent closest relatives in the subtribe Myrtinae is discussed. Through studies of American Myrtaceae of the subtribe Myrtinae it has become evident that Myrtus elegans DC. cannot be realistically assigned to any existing genus. Therefore, I here describe a new genus, Accara, to accomodate it. In addition to Myrtus, the species in question has been placed in Psidium by two authors. Ac- cara is out of place in both genera. Psidium has a set of seed coat characters that distinguishes it from other genera (Landrum and Sharp 1989). Accara clearly differs from Psidium in having seed coats with a smooth, lustrous outer surface, the hard portion of the seed coat only one cell thick at its narrowest point, and the cells of the seed coat about 1-3 times as long as wide (figs. 1, 2). Accara and Psidium also differ in embryo structure and in being tetramerous and pentam- erous, respectively. Myrtus, while having es- sentially the same embryo structure as Accara and a similar seed coat, differs in being pentam- erous and in having the calyx-lobes unfused in