The neotropical genera of Marantaceae. Circumscription and relationships

The delimitation of the neotropical genera of the Marantaceae has been revised, using evidence mainly from the morphology of inflorescences and flowers. It is concluded that the generic concepts of Schumann in “Das Pflanzenreich”, often questioned by 20th century American authors, are essentially sound, but that his grouping of the genera into two tribes is quite artificial. Main deviations from the treatment of Schumann are the rearrangement of the genera, somewhat different stress on diagnostic characters and a much narrower concept of the genus Myrosma. A new genus, Koernickanthe is proposed for the long known species Maranta orbiculata (Koern.) Schum. The genera are arranged into informal groups and the groups and genera recognized are: Maranta group (Maranta L., Monophyllanthe Schum.), Myrosma group (Myrosma L. f., Saranthe (Regel et Koern.) Eichl., Hylaeanthe Jonker et Jonker, Ctenanthe Eichl., Stromanthe Sond.), Calathea group (Calathea G. F. W. Meyer, lschnosiphon Koern., Pleiostachya Schum.), Monotagma group (Monotagma Schum., Koernickanthe gen. nov.) and Thalia “group” (Thalia L.). It is suggested, that each group has its closest affinities with Old World genera and that this indicates that the diversification of the marantaceous stock was far–reaching already before the Old and the New World became effectively isolated. It is further suggested that the early diversification of the family took place in Africa, the flora of which, although poor in species, is morphologically very diverse. Two new combinations are made, viz. Stromanthe stromanthoides (Macbr.) Anderss. and Koernickanthe orbiculata (Koern.) Anderss.