Candelariaceae is a family of lichen-forming fungi in the order Candelariales. It contains seven genera and about 73 species of lichens that are typically characterised by their bright yellow colour. These lichens have diverse growth forms, including crusty, scaly, and small leaf-like structures, and are found worldwide, particularly in arid and mountainous regions of both hemispheres. The family includes well-known genera such as Candelaria, Candelariella, and Placomaronea, with their classification continuing to evolve based on molecular studies. Recent phylogenies find Candelina and Placomaronea to be well supported, but many relationships among Candelaria and Candelariella lineages remain unresolved.
Taxonomy
The Finnish lichenologist Rainar Hakulinen proposed Candelariaceae in 1954 when he removed the bright-yellow foliose genus Candelaria from Parmeliaceae and united it with the crustose Candelariella and the umbilicate Placomaronea. Candelaria had formerly been placed in the Parmeliaceae by Alexander Zahlbruckner in 1926, while the crustose lichen genus Candelariella was classified among the crustose Lecanoraceae. The family remained morphologically delimited until Josef Poelt (1974) showed that cortex anatomy separated the placodioid Candelina—which has a densely pigmented outer cortex—from Placomaronea, where the cortex is paraplectenchymatous and capped by "peppered" pigment hoods. Early molecular work (Westberg et al. 2007) confirmed the monophyly of the family within Candelariales and recovered well-supported clades corresponding to Candelina and Placomaronea, but also revealed that Candelariella in its traditional sense is paraphyletic.
Subsequent phylogenies that sampled a wider array of internal transcribed spacer (ITS) sequences reiterated these patterns and showed that the ability to produce more than eight ascospores per ascus (polyspory) has evolved repeatedly inside the family. In an effort to impose monophyly, in 2020 Sergey...
