[7] Sherwood in 1977 proposed to maintain a distinction between the Graphidales with mostly lichenised members and the Ostropales which included mostly non-lichenised fungi, based on different spore septation types.

[21] In 2004, the phylogenetic relationships of class Lecanoromycetes were examined by using mitochondrial small subunit ribosomal DNA sequencing which found that orders Graphidales and Ostropales were monophyletic.

[24][25] However, Kraichak et al. in 2018,[26] ranked Graphidales as a separate order based on a temporal approach, and accepted five families; Diploschistaceae, Fissurinaceae, Gomphillaceae, Graphidaceae and Thelotremataceae.

[32][33] The Graphidaceae are mostly epiphytic lichens with trentepohlioid photobiont (i.e., filamentous, multicellular green algae from genus Trentepohlia),[34] and graphidoid, distoseptate (forming a layer) ascospores.

[35][36] Family Gomphillaceae was originally based on a single species, Gomphillus calycioides (Watson, 1929), which is an unusual taxon growing over bryophytes.