Tetrodontium

…in the Northern Hemisphere, with Tetrodontium also present, but rare, in the Southern Hemisphere; 1 order, 2 genera, Tetraphis and Tetrodontium, with 3 or 5 species. The family Calomniaceae (1 genus, with about 9 species) is sometimes included in this subclass. Subclass Polytrichidae Sporophytes with elongate rigid seta containing conducting…