The Collemataceae are a lichenized family of fungi in the order Peltigerales. The family contains ten genera and about 325 species. The family has a widespread distribution.

Collema is a genus of lichens in the family Collemataceae. The photobiont is the cyanobacterium genus Nostoc. Species in this genus typically grow on nutrient-rich bark or somewhat siliceous or calcareous rocks in humid environments.