These are in most cases rather enduring and robust mosses on rocks. Most species form compact cushions, but there are also species, in which one can see a transition to pleurocarpy, and which develop decumbent, short stems. They prefer very bright, sunny locations. In the tropics they can only be found in the high mountains. Many species can stand long and extreme dryness.
The leaves of the plants of this family are oval or lanceolate and often end in a long, hyline tip or hair. A midrib always exists. It ends in the tip of the leaf. The cells of the blade are in most cases round. The differentiation between the species follows the form of the leaves.
The capsules are ovoid or cylindrical. In most cases the peristome consists of 16 well developped teeth.