An order of the Ascolichenes. This order is characterized by an unusual apothecium. The hymenial layer originates normally, but by the time the spores are mature, the asci and paraphyses have partially disintegrated into a mass of spores and hymenial tissues known as a mazaedium. In the family Caliciaceae the disk is borne on a short stalk 0.04–0.32 in. (1–8 mm) high, a peculiar structure that is also known in the nonlichenized Roesleriaceae. These two families are so close that some species in either one may or may not lichenize symbiotic algae. The primary thallus of the Caliciaceae is a powdery grayish or lemon-yellow crust on soil or rotten wood. There are six genera separated by spore septation and color. The family Cypheliaceae with seven genera is more typically crustose, with sessile apothecia and a more fully developed thallus. The Sphaerophoraceae are fruticose, much like Cladonia sp., but the thallus is solid. The apothecia are open or enclosed in a spherical chamber at the tips of branches. The largest genus, Sphaerophorus, is widespread in boreal zones and mountains of both hemispheres.