The name of the genus, circumscribed in 1968 by the husband and wife lichenologists William and Chicita Culberson, alludes to the former placement of these species in the genera Cetraria and Parmelia.

The main characteristics of the genus are the broad, rounded lobes of the greyish-green lichen body, and the presence of tiny pores in the outer surface (the cortex) that enable gas exchange.

They prefer somewhat moist, cool habitats, and are most commonly found on tree trunks, but sometimes on rocks or on bryophytes over shaded boulders.

In 1960 they started a study of the genus Cetraria in the broad sense, as it had been defined by Alexander Zahlbruckner in his 1930 work Catalogus Lichenum Universalis.

[4] According to a 2012 review of the family Parmeliaceae, the creation of these three new more natural genera by the Culbersons initiated "a trend of splitting that continued for more than three decades".

[5] In the early 1970s Josef Poelt developed the concept of "species-pairs"—taxa that are morphologically and chemically similar (if not identical), but differ primarily in their reproductive modes: one taxon reproduces sexually, the other vegetatively.

[8] In a 2019 phylogenetic analysis, these chemotypes were named according to their major medullary substance(s): imbricaric, olivetoric, anziaic, perlatolic, microphyllinic, and alectoronic + α-collatolic.

[12][13] Cetrelia species are commonly known as sea-storm lichens;[14] according to author Colin Rees, "the greenish-gray uplifted edges of its lobes are reminiscent of foam on ocean waves".

Morphological characteristics that unite these three genera include the presence of large, broad, rounded lobes, and thalli that are usually oriented horizontally.

Cetrelia produces a constant set of polyphenolic compounds of still unknown function, specifically orcinol-type depsides and depsidones.

Character state analyses showed that metabolites in Cetrelia seem to be evolving towards more complex substances, indicating possibly their evolutionary importance in the survival or functioning of the species.

[14] Other secondary chemicals that have been identified in this genus are: alectoronic, anziaic, collatolic, imbricaric, microphyllinic, olivetoric, perlatolic, and physodic acids.

For example, flavoxanthin, detected in the thalli of C. japonica, had previously only been found in three other instances, although it is not uncommon in the blossom and fruit of higher plants.

[22] The presence or absence of reproductive propagules such as isidia, soredia, and lobules are important physical characters in the taxonomy of Cetrelia.

Although superficially similar, Cetreliopsis lichens have a distinct secondary chemistry: they contain usnic acid in the upper cortex, and orcinol depsidones in the medulla.

[12][22][27][28][5] Based on the distribution of the majority of the chemotype and morphotype combinations, the centre of speciation in Cetrelia is thought to be southern and eastern Asia.

[46] In general, the genus prefers somewhat moist, cool habitats, and is often found on tree trunks or bryophytes over shaded boulders.

[47] Cetrelia species found in Europe are largely epiphytic (growing on plants), usually encountered in old natural or seminatural forests on tree bark, and sometimes on mossy rocks.

[54] Cetrelia olivetorum has been included in the Legislative List of Legally Protected Lichens of Latvia, a status that allows for the establishment of small nature reserves (up to 30 hectares (74 acres)) to aid in its conservation.

Depending on the type of method used to extract the lichen dye, it produces a final colour of ivory yellow or light yellowish olive.

[58] Atranorin is one dye-producing substance found in this species;[59] alectoronic and α-collatolic acid are additional secondary chemicals that occur in C. braunsiana.

[30] In China, Cetrelia cetrarioides, C. olivetorum, and C. pseudolivetorum are collected in bulk for the preparation of material with antibiotic-like properties used in traditional medicine.