Oletheriostrigula Huhndorf & R.C. Harris, Brittonia 48: 551 (1996).
MycoBank number: MB 27751; Index Fungorum number: IF 27751; Facesoffungi number: FoF 08925.
Type species: Oletheriostrigula papulosa (Durieu & Mont.) Huhndorf & R.C. Harris, Brittonia 48: 551 (1996); Sphaeria papulosa Durieu & Mont., Expl. Sci. Alg., Fl. Algér. 1(14): 536 (1848) [1846–49]; Leptosphaeria papulosa (Durieu & Mont.) Sacc., Nuovo G. Bot. Ital. 7: 313 (1875); Metasphaeria papulosa (Durieu & Mont.) Sacc., Syll. Fung. 2: 168 (1883); Massarina papulosa (Durieu & Mont.) S.K. Bose, Phytopath. Z. 41: 176 (1961).
Notes: Huhndorf and Harris (1996) suggested placement of this unique, non-lichenized, apparently saprotrophic fungus in Strigulaceae, based on hamathecium and ascus structure. Close relationship of non-lichenized and lichenized fungi has been demonstrated for other lineages, such as Heleiosa in the Monoblastiaceae (Nelsen et al. 2011a; Lücking et al. in Hongsanan et al. 2020, this volume; Monoblastiaceae). The paraphyses, asci and ascospores of Oletheriostrigula indeed closely resemble those of e.g. Flavobathelium. However, based on Bose (1961), Huhndorf and Harris (1996) gave the asexual morph of Oletheriostrigula as Diplodia stage, which is described as forming rather large (around 20–40 × 10–15 µm), aseptate, oval-ellipsoid, rather thick-walled conidia that remain mostly hyaline but partially become brown and septate with age and never produce gelatinous appendages (Burgess et al. 2003; Alves et al. 2004; Damm et al. 2007; Phillips et al. 2007). Bose (1961) described the conidia of Massarina populosa as 7–16 × 2.5–5 µm in size, gradually (not abruptly in age) turning brown, and irregularly pyriform-clavate to elliptical, thus different from Diplodia sensu stricto. Even so, while the conidia of Oletheriostrigula do not seem to represent a genuine Diplodia asexual morph, they are also very different from macroconidia in Strigulaceae, which are septate to muriform, persistently hyaline, and with gelatinous appendages; hence Oletheriostrigula must be excluded from that family.