Revision and Morphological Phylogeny of Ephedranthus, a Neotropical Genus of Annonaceae

Abstract

Ephedranthus S. Moore is a Neotropical genus of Annonaceae distributed from Colombia and the Guianas to Bolivia and southeastern Brazil, comprised of seven species: E. amazonicus R. E. Fr., E. boliviensis Chatrou & Pirie, E. colombianus Maas & Setten, E. dimerus J. C. Lopes, Chatrou & Mello-Silva, E. guianensis R. E. Fr., E. parviflorus S. Moore, and E. pisocarpus R. E. Fr. The genus is recognized by the combination of leaves with impressed adaxial veins, short pedicels, two to five bracts, androdioecy (i.e., some plants with only staminate flowers, other plants with only bisexual flowers), and 1-seeded monocarps. This revision updates the knowledge about the genus, providing a morphological phylogenetic analysis of Ephedranthus species, with a key, descriptions, distribution maps, and illustrations of the diagnostic characters of the species. The phylogenetic analysis shows Ephedranthus defined by having staminate flowers and basal placentation, and the seven species related as ((E. colombianus, E. boliviensis) ((E. guianensis, E. amazonicus) (E. dimerus (E. parviflorus, E. pisocarpus)))); based on this, the current subdivision of Ephedranthus is not monophyletic, and the sections are here synonymized.