Pleurocarpous Mosses (Mat-Forming)

This group gathers Mosses and Liverworts subcategory members belonging to the pleurocarpous mosses, a growth form defined by a creeping or freely branching main stem that produces its spore-bearing capsules from short side branches along its length rather than from the stem tip, letting the main stem keep growing indefinitely even as it reproduces. It spans the feather mosses of the family Hylocomiaceae, whose intricately, repeatedly branched fronds form some of the thickest, most luxuriant moss carpets found on forest floors in cooler climates, and the aquatic mosses of the genus Fontinalis, which grow submerged, trailing long strands in flowing streams and still water alike. Nearly every family gathered here spreads horizontally to form extensive mats, carpets or hanging curtains of growth rather than the compact cushions and tufts typical of the acrocarpous mosses gathered separately, and this sprawling, indeterminate growth habit is what gives the pleurocarpous mosses their common informal name of carpet or weft mosses.