New species and a new record of Orthotrichum from southern Africa: O. incurvomarginatum sp . nov., O. armatum sp. nov., O. oreophilum sp. nov. and O. firmum Vent.

Abstract

Orthotrichum incurvomarginatum, O. armatum and O. oreophilum all belonging to subgenus Phaneroporum section Leiocarpa are described from South Africa. O. incurvomarginatum replaces O. afro-fastigiatum sensu Lewinsky, whereas O. afrofastigiatum C. Müll is regarded as a dubious name. O. armatum is characterized by aristate leaves with recurved margins and emergent to shortly exserted capsules which are ribbed when dry. O. oreophilum has longly exserted smooth capsules with eight exostome teeth and eight endostome segments, both with a coarse ornamentation of papillae and vermicular ridges. O. firmum is reported new to South Africa, O. rupestre new to the kingdom of Lesotho.