Leptosillia Höhn., Mitt. bot. Inst. tech. Hochsch. Wien 5: 111 (1928)
Xylariomycetidae, Amphisphaeriales, Leptosilliaceae, Leptosillia
Index Fungorum number: IF2797; Facesoffungi number: FoF 06205; 9 morphological species; 6 species with sequence data.
Endophytic, pathogenic or lichenized. Sexual morph: Ascomata perithecial, globose to subglobose to pyriform, superficial to partly immersed, scattered or aggregated, black, at times collapsed, ostiolate. Ostiole central, papillate, sulcate, hyaline periphyses sometimes present at the base. Peridium melanized, KOH-, comprising dark brown, thick-walled cells of textura angularis or prismatica, becoming subhyaline towards the center. Paraphyses septate, sometimes branched, hyaline, embedded in a gelatinous matrix. Asci 8-spored, clavate to cylindrical, curved or sinuous, short-pedicellate, comprising an indistinct and generally J- refractive apical ring. Ascospores 2- or 3-seriate or fasciculate, hyaline, falcate, lunate, sinuous, sigmoid to hook-shaped, aseptate or septate, not constricted, thin and smooth-walled, comprising rounded to subacute apices, lacking appendages or gelatinous sheath. Asexual morph: Coelomycetous. Conidiomata superficial to partly immersed, scattered, aggregated or confluent, globose to pyriform, uni- or occasionally pluriloculate, black. Conidiomatal wall more or less melanized, light to dark brown, made up of thin-walled cells of textura globulosa or angularis. Conidiophores hyaline, short, originating from the inner layer of the conidiomatal wall. Conidiogenous cells cylindrical to lageniform. Conidiogenesis usually of two types: either enteroblastic-phialidic, giving rise to filiform to narrowly falcate conidia or holoblastic with sympodial proliferation, producing allantoid to falcate conidia. Conidia allantoid to falcate to filiform, aseptate, hyaline, thin-walled, smooth (adapted from Voglmayr et al. 2019a).
Type species: Leptosillia notha Höhn., Mitt. bot. Inst. tech. Hochsch. Wien 5: 111 (1928)
Notes: When establishing Cresporhaphis, a synonym of Leptosillia, Aguirre-Hudson (1991) described its association with an unidentified globose chlorococcoid photobiont. Various species were included, as probably lichenized and Calatayud & Aguirre-Hudson (2005) considered Cresporhaphis ulmi as not lichenized. Voglmayr et al. (2019a) introduced seven species as new combinations in Leptosillia. Species of Leptosillia have superficial to partly immersed, subglobose to pyriform, ostiolate ascomata, with a peridium of textura angularis or prismatica, and clavate to cylindrical asci and lunate ascospores. The asexual morph has superficial conidiomata with cells of textura globulosa to angularis in the conidiomatal wall, short hyaline conidiophores, cylindrical to lageniform conidiogenous cells and lunate or filiform conidia (Voglmayr et al. 2019a).
Leptosillia muelleri (Duby) Voglmayr & Jaklitsch