Halotthia Kohlm., Nova Hedwigia 6: 9 (1963).
MycoBank number: MB 2212; Index Fungorum number: IF 2212; Facesoffungi number: FoF 08248; 1 morphological species (Species Fungorum 2020), 1 species with molecular data.
Type species – Halotthia posidoniae (Durieu & Monta.) Kohlm., Nova Hedwigia 6: 9 (1963)
≡ Sphaeria posidoniae Dur. & Mont., Expl. Sci. Alg., Fl. Algér. 1(livr. 13): 502 (1848) [1846-49].
Notes – Halotthia typified by H. posidoniae was initially described as Sphaeria posidoniae. It was transferred to Pleosporaceae by Kohlmeyer & Kohlmeyer (1979). Malloch & Cain (1972) referred the genus to Zopfiaceae, and Jones et al. (2009a) placed it in the Pleosporales incertae sedis. Based on multi-gene analysis with LSU, rpb-2, SSU and tef1, Suetrong et al. (2009) showed it groups with Pontoporeia biturbinata in the Pleosporales, both genera commonly found on Posidonia oceanica and Cymodocea nodosa from the Mediterranean coast and Cyprus (Suetrong et al. 2009). Suetrong et al. (2009) did not assign it to any order and family until Zhang et al. (2013c) introduced Halotthiaceae with Halotthia posidoniae as the type genus.
Species