Mylchyaceae

Mylchyaceae is a name that has historically been used for a family of mosses in bryophyte classification. In different taxonomic treatments the group has been treated as a distinct family within the class Bryopsida and order Hypnales, or as a synonym or subfamily of larger moss groups. Over time, molecular phylogenetic studies have led to rearrangements, and many genera once placed in Mylchyaceae have been reassigned to related families such as Hypnaceae, Amblystegiaceae, or in some schemes to other groups within Hypnales.

The morphology of members traditionally placed in Mylchyaceae is that of small to medium-sized mosses forming carpets, cushions, or tufts on moist substrates. Leaves are typically lanceolate to deltate with a well-developed costa; sporophytes produce capsules on slender setae, often with peristome structures that aid in spore dispersal. Because of the variable nature of moss taxonomy, there is no single diagnostic feature that is universally applied to all genera once included in Mylchyaceae.

Geographically, species associated with the name have been reported in temperate regions across the Northern Hemisphere and in subtropical to boreal environments, frequently in moist, shaded habitats such as forest floors, wetlands, riverbanks, and decaying wood. They commonly occur on soil, rock, or bark, sometimes as epiphytes.

Current usage: The status of Mylchyaceae as a formal, natural family varies by taxonomy; modern bryologists may treat it as a synonym or an infrageneric grouping within broader families. For precise circumscription, consult current taxonomic databases or flora treatments.