Candelariaceae is a family of lichen-forming fungi in the order Candelariales. It contains seven genera and about 73 species.
The family was circumscribed by Finnish lichenologist Rainar Hakulinen in 1954 to contain the type genus, Candelaria. This genus had formerly been placed in the Parmeliaceae by Alexander Zahlbruckner in 1926, while the crustose lichen genus Candelariella was classified among the crustose Lecanoraceae. Hakulinen also included the genus Placomaronea, which contains species.
The Candelariaceae family exhibits a diverse range of growth forms, including crustose,, -, and thalli, typically characterized by their bright yellow colour. The in these lichens is, contributing to their photosynthetic abilities. The reproductive structures, or ascomata, are predominantly apothecia, although apothecia are also found in some instances.
The, which is part of the ascomata, is made up of unbranched or slightly branched, amyloid . The asci, or spore-bearing structures, have an apical with an amyloid outer wall. The tholus is weakly amyloid, except for the darker, strongly amyloid lower portion, and is typically in shape. Each ascus contains 8 to 64, which are either non-septate or indistinctly 1-septate. These spores are hyaline, non-amyloid, and vary in shape from ellipsoid to (lemon-shaped).
Candelariaceae lichens also produce, which are -containing structures. The, or asexual spores, are non-septate, hyaline, and range in shape from ellipsoid to (rod shaped), sometimes exhibiting a curved form. The secondary chemistry of Candelariaceae lichens includes derivatives of pulmonic acid, a lichen product that contributes to their unique characteristics.