Schismatomma Flot. & Körb. ex A.Massal.
Thallus crustose, homoiomerous, ecorticate. Photobiont green, Trentepohlia (thallus shows orange-yellow when scratched, colour fades on storage, best seen in fresh material) with or without soredia. Apothecia sessile, round to irregular, ± stellate, furcate or lirellate, innate to emergent and with a distinct thalline margin, disc black or brownish, epruinose. Hypothecium colourless to redbrown or blackish. Paraphyses slender, sparingly branched, brownish at apices. Asci clavate cylindrical with a tapering foot, apex with a dimple. Ascospores 8 per ascus, 3-septate, colourless, acicular-fusiform, sometimes curved.
Schismatomma is a cosmopolitan genus of c. 85 species, included in the family Lecanactidaceae although it has affinities with the families Opegraphaceae and Rocellaceae [Huneck and Follmann Ber. dtsch. bot. Ges. 81: 125-134 (1968)]. The genus is not well delimited from Enterographa, Lecanactis and Opegrapha [Coppins and James Lichenologist 11: 27-45 (1979)]. It has an interesting chemistry [Huneck and Follmann loc. cit. (1968); James and Coppins Lichenologist 11: 253-262 (1979)] showing affinities with Dirina, Lecanactis and Roccella.
In 19th century accounts of New Zealand lichens, species of Schismatomma were classified as Platygrapha. Three species are here recorded from New Zealand, where the genus is very poorly known and collected, and much in need of study and revision.
