A genus of mosses, in which the ovate or lanceolate leaves have a border of long, narrow cells, with double teeth along the leaf margins (visible under the microscope). There is a nerve which ends in the leaf tip with a tooth at the back. There are about 12 species, found mostly in the northern hemisphere. M. hornum is one of the most abundant of British mosses, forming extensive carpets in woodland on peaty acidic soil, rotting wood, etc. Normally it is a dull, dark green, although the young shoots that grow in spring are a contrasting bright green. (A number of species formerly included in this genus are now allocated to other genera: e.g. M. undulatum is now called Plagiomnium undulatum and M. punctatum is now Rhizomnium punctatum.)
Subjects: Plant Sciences and Forestry.