Placentation and aestivation have traditionally been used as diagnostic features to separate the genera Ardisia Swartz and Stylogyne A.DC. While Ardisia has pluriseriate placentation and imbricate or quincuncial aestivation, Stylogyne has uniseriate placentation and contorted aestivation. However, careful examination of ten species of these genera revealed the inconsistency of these characters in the distinction of the two genera. Also, we noticed the impossibility of observation of placentation types in few-ovuled specimens. Therefore, we propose the re-establishment of the circumscription of Ardisia adopted by Miquel, in 1856, and Handro, in 1969 which includes the genus Stylogyne. In this way Ardisia ambigua Mart. is the valid name for S. ambigua (Mart.) Mez as Ardisia martiana Miq. is for S. laevigata (Mart.) Mez. Two new combinations are necessary: Ardisia depauperata (Mez) Bernacci & Jung-Mendaçolli and Ardisia warmingii (Mez) Bernacci & Jung-Mendaçolli.
Ardisia; Stylogyne; Myrsinaceae; Southeastern Brazil; taxonomy
