A PHYLOGENETIC EVALUATION OF SECTS. AGROSTOIDEA, MEGISTA, PRIONITIA AND TENERA OF PANICUM (PANICOIDEAE, POACEAE): TWO NEW GENERA STEPHOSTACHYS AND SORENGIA

ZULOAGA, F.O.; SCATAGLINI, A.M.; MORRONE, O.

TAXON

INT ASSOC PLANT TAXONOMY

Año: 2010 vol. 59 p. 1535 - 1546

0040-0262

The taxonomic features of species of Panicum, previously classified in sects. Megista, Tenera, Prionitia and Agrostoidea, subg. Agrostoidea and Phanopyrum of Panicum, are here reviewed and compared with Panicum s. s. and other taxa of Paniceae. All taxa, previously considered in these sections, are now included in the new genera Stephostachys and Sorengia, which are based on morphological and molecular characters. Stephostachys includes one species, S. mertensii (Roth) Zuloaga & Morrone, ranging from Mexico to Argentina, while Sorengia comprised seven species, S. anceps (Michx.) Zuloaga & Morrone,  S. caricoides (Nees ex Trin.) Zuloaga & Morrone, S. petersonii (Hitchc. & Ekman) Zuloaga & Morrone, S. prionitis (Nees) Zuloaga & Morrone, S. rigidula (Bosc ex Nees) Zuloaga & Morrone, S. stenodes (Griseb.) Zuloaga & Morrone, and S. tenera (Beyr. ex Trin.) Zuloaga & Morrone, distributed from the United States to Bolivia and Brazil. Affinities of the new genera with other genera of Paniceae are also discussed. Lectotypes are designated for Panicum caricoides var. glabriusculum Döll, P. pilosum Döll, P. prionitis Nees, P. prionitis var. varium Kuntze, and P. stenodes Griseb.