Taxonomical revision of the species of the genus Schizachyrium Nees (Poaceae: Andropogoneae) of South America

摘要

A taxonomical revision of the genus Schizachyrium Nees in South America is presented. Twenty-two taxa are recognized, ranging from Colombia and Venezuela to Rio Negro province in Argentina. The identity of Schizachyrium bimucronatum Roseng. & al., Schizachyrium lactiflorum (Hack.) Herter, and Schizachyrium plumigerum (Ekman) Parodi, is reevaluated and these taxa are accepted. A new species Schizachyrium glaziovii Peichoto is described and illustrated. Two new combinations are validated: Schizachyrium salzmannii var. aristatum (Hack.) Peichoto, and Schizachyrium tenerum var. hirtiglume (Henrard) Peichoto. A lectotype is chosen for the names Andropogon condensatus subvar. latens Hack., Andropogon condensatus subvar. lactiflorus Hack., Andropogon feensis E. Foum., Andropogon schottii Hack., Andropogon schottii subvar. asperightmis Hack., Andropogon semiberbis var. incertus Hack., Apogonia glabrata(' E. Foum., Deyeuxia spicata Spreng. and Schizachyrium tenerum Nees. A neotype is chosen for the names Schizachyrium weberbaueri Pilg. and Schizachyrium weberbaueri var. minus Pilg. The area of distribution of Schizachyrium spicatum is extended in Argentina and the species is recorded for the first time for Chile. Schizachyrium hatschbachii Peichoto is mentioned for the first time from Paraguay and Schizachyrium semitectum (Swallen) Reeder from South America. A diagnostic key for recognizing species and varieties is given, and the description, illustrations, geographical distribution, ecological observations and vernacular names for each species are provided.