Cleistocarpous Tortella species from South America comprise a new genus of Pottiaceae

Abstract. Anaschisma, a new genus of Pottiaceae, is distinguished from both Tortella and Trichostomum by the caducous, cleistocarpous capsule, and from Aschisma by capsule dehiscence irregular, not circumscissle. It is similar to Aschisma in the denticulate, weakly bordered cauline leaves, broadest at the base, and tendency to secund leaf stance. Four species of South America comprise the genus, two of them new to science. The new genus is an apparent descendant of Trichostomum brachydontium because gametophytes are nearly identical but unlike other species of that genus. Trichostomum planifolium is newly reported for Brazil. Corrections are made to a previous treatment.