STUDIES IN SOUTH AMERICAN AMARANTHACEAE V

Abstract

The nomenclature, taxonomy, and synonymy of various South American Amaranthaceae are discussed. Two new genera are described, Hebanthodes Pedersen with only one new speciesfrom Peru, H. peruviana Pedersen, and Lecosia Pedersen with two new species from NE Brazil, L. formicarum Pedersen and L. oppositifolia Pedersen. Seven new species, Alternantherapiptantha Pedersen, Gomphrena Hatschbachiana Pedersen, G. riparia Pedersen, Guilleminea chacoensis Pedersen, G. fragilis Pedersen, G. hirsuta Pedersen and Pfaffia argyrea Pedersen, one new subspecies, Alternanthera Kurtzii subsp. sclerosperma Pedersen, and three varieties, Alternanthera hirtula var. hirsuta Pedersen, Alternanthera hirtula varo nitens Pedersen and Pfaffia fruticulosa varo diffusa Pedersen are described. Three new combinations, Hebanthe eriantha (Poir.) Pedersen, Iresine diffusa forma Herbstii (Hook.) Pedersen, and Pedersenia Hassleriana (Chodat) Pedersen, are proposed. A key to the species of Guilleminea discussed in this paper and a key synthesizing the characters separating Hebanthodes from its immediate allies are provided.