Distinctive characteristics of species in the Schaereria genus include a crustose to squamulose thallus, ascomata (fruiting bodies) with a blackened ring and a blackish disk, and asci (spore-bearing cells) that lack tholus (a thickened part of the inner wall near the tip).
The secondary chemistry of the genus produces specific substances, including the pigment known as Cinereorufa-green in Schaereria cinereorufa.
The genus, having a cosmopolitan distribution, primarily favours cold to cool climates of the Northern Hemisphere.
[4] Despite this, Schaereria was accepted a few years later (in 1860) by Theodor Magnus Fries, who used it in his work on Arctic, European, and Greenlandic lichens.
The family Schaereriaceae was first proposed by French lichenologist Maurice Choisy in 1949, but he did not publish the name validly as it did not meet the criteria for publication as determined by the International Code of Nomenclature for algae, fungi, and plants.
[13] Hafellner noted some similarities in the characteristics of the hymenium between the Schaereriaceae and the order Pezizales,[13] and the family was included there in the 1985 version of the Outline of the Ascomycota.
[16] Molecular studies that have included Schaereria species have shown that it occupies a relatively isolated phylogenetic position.
[19][20] In a critical review of the temporal method for lichen classification, Robert Lücking found flaws in their analysis and rejected the proposed split, instead retaining both Sarrameanaceae and Schaereriaceae in the Sarrameanales.
These include: a thallus that is crustose to squamulose; a trebouxioid photobiont partner (spherical unicellular green algae); ascomata being lecideine (having an apothecium which lacks algae and lacks an amphithecium); apothecia that are hemiangiocarpous (meaning they open before the spores are mature); and a cup-shaped excipulum.
[22] The identification of species within Schaereria is primarily based on specific traits: the chemical composition and form of the thallus, the colouration of the apothecia, and the distinctive shape and organization of ascospores within the ascus.
For instance, Schaereria cinereorufa is characterised by a squamulose to bullate (blistered) thallus, often found on siliceous rocks, with sessile or marginally located apothecia.
In contrast, S. corticola has a sparsely developed, endo- to episubstral thallus with soredia and sessile apothecia.
Schaereria fuscocinerea, somewhat intermediate, features an areolate thallus on siliceous rocks, and its fruiting bodies are either immersed in or between areolae.
In S. fuscocinerea, ascogonia with trichogynes appear in the algal layer, with subsequent growth of paraphysoids, followed by the differentiation of ascogenous hyphae and true paraphyses.