CHORISODONTIUM (DICRANACEAE, MUSCI) IN SOUTHERN SOUTH-AMERICA

The genus Chorisodontium (Mitt.) Broth. in southern South America is revised. Five species are present in the area, C. aciphyllum (Hook. f. & Wils.) Broth., C. dicranellatum (C. Mull.) Broth., C. luridum Bartr., C. magellanicum (Card.) Bartr. and C. spegazzinii (C. Mull.) Roiv. For each species a brief description and diagnosis are given, the distribution is outlined and the ecology discussed. A key to the species in southern South America is given. The type specimens are indicated and the nomenclature discussed. The lectotype is selected for C. sphagneticola Roiv. (= Chorisodontium aciphyllum). Six names are given as new synonyms. A provisional cladistic analysis of the whole genus is presented.