Polychidium

Polychidium
	Polychidium muscicola
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Lecanoromycetes
Order:	Peltigerales
Family:	Massalongiaceae
Genus:	Polychidium; (Ach.) Gray (1821)
Type species
	Polychidium muscicola; (Sw.) Gray
Species
	P. cetrarioides; P. dactylinum; P. muscicola; P. pulvinatum
Synonyms
	List Collema †††††††† Polychidium Ach. (1810) ; Collema sect. Polychidium (Ach.) Bory (1823) ; Garovaglia Trevis. (1853) ; Pilonema Nyl. (1858) ; Garovaglina Trevis. (1880) ; Leptodendriscum Vain. (1890) ; Pseudoleptogium Jatta (1900) ; Wilsonia Cheel & Dughi (1944) ; Leptogidiomyces Cif. & Tomas. (1953) ; Colleptogium sect. Polychidiopsis M.Choisy (1962) ;

Polychidium is a genus of lichen-forming fungi in the family Massalongiaceae. These lichens form tiny, shrub-like tufts with branching filaments that create woolly cushions on moss-covered rocks and tree twigs. The genus was traditionally thought to include four similar-looking species, but molecular studies revealed that three of these actually belong to a different genus called Leptogidium. Today, Polychidium in the strict sense contains only P. muscicola and three closely related species, found from tropical to subarctic regions worldwide.