Anthostomella Sacc., Atti Soc. Veneto-Trent. Sci. Nat., Padova, Sér. 4 4: 84 (1875)
Synonymy: Appendixia B.S. Lu & K.D. Hyde, Fungal Diversity Res. Ser. 4: 224 (2000)
= Myconeesia Kirschst., Annls mycol. 34(3): 200 (1936)
Index Fungorum number: IF 226; Facesofungi number: FoF 00316
Saprobic on wood, branches and twigs or endophytic on leaves. Sexual morph: Ascomata immersed or semi-immersed, globose-conical, solitary or aggregated, dark, clypeate, coriaceous, ostiolar canal with periphyses. Peridium comprising compressed, angular or irregular cells, outwardly comprising thick-walled, dark brown cells, inwardly comprising thin-walled, hyaline cells. Paraphyses numerous, filamentous, hyaline, unbranched, septate, embedded in a gelatinous matrix. Asci 8-spored, unitunicate, cylindrical-clavate, short-pedicellate or sometimes apedicellate, with a J+ or J- apical ring or occasionally lacking a visible apical ring. Ascospores uniseriate or overlapping uniseriate or occasionally biseriate, uni-bicellular, ellipsoidal-inequilaterally ellipsoidal, brown-dark brown, when basal dwarf cell present larger cell brown and small cell hyaline, sometimes with hyaline appendages at the ends, smooth-walled, sometimes surrounded by a mucilaginous sheath, germ slit straight, spiral or sometimes lacking. Asexual morph: Conidiophores simple, light brown, branched or single. Conidiogenous cells few, small, disc-shaped, denticulate. Conidia hyaline, easily dehiscent, ellipsoidal, unicellular.
Type species: Anthostomella limitata Sacc., Atti Soc. Veneto-Trent. Sci. Nat., Padova, Sér. 4 4: 101 (1875)
Notes: Anthostomella is a heterogeneous genus with approximately 85 species (Lu and Hyde 2000; Daranagama et al. 2015, 2016e). Many species are distributed in tropics, subtropics and even temperate regions. A world monograph of Anthostomella was published by Lu and Hyde (2000). The phylogenetic placement of Anthostomella was established in Daranagama et al. (2015, 2016e) based on molecular data. However, it should be noted that true affinities of many species are still doubtful as they are illustrated only in a morphological perspective. Since many species lack living cultures particularly those described in earlier decades, obtaining sequence data is not possible until fresh collections become available.
The genus is characterized by immersed, dark, clypeate ascomata with periphysate ostiolar canals, 8-spored, cylindrical, unitunicate asci and mostly dark, unicellular ascospores, sometimes with dwarf cells or appendages at the ends (Daranagama et al. 2016e). Appendixia is a monotypic genus introduced by Lu and Hyde (2000) to accommodate Sphaeria closterium Berk. & M.A. Curtis, with ascospores having two long polar appendages. Appendixia closterium has similar ascomatal characters to Anthostomella such as immersed, coriaceous ascomata with a clypeus. Even though a cylindrical apical ring in ascus of A. closterium was mentioned by Lu and Hyde (2000), we have only observed a J+ apical ring slightly bluing in Melzer’s reagent, which is also similar to Anthostomella species. Wendt et al. (2017) listed Appendixia in Xylariales incertae sedis due to the lack of molecular data and unknown asexual morph characters. However, based on its morphological similarities with the Anthostomella sensu stricto described above we tentatively synonymized Appendixia with Anthostomella until the placement is confirmed by molecular data.
The asexual morph of several Anthostomella is characterized by conidiophores that are simple, light brown, branched or single and having a few, small, disc-like, denticulate conidiogenous cells and hyaline, easily dehiscent, ellipsoidal, unicellular conidia (Daranagama et al. 2015).
Daranagama DA, Hyde KD, Sir EB, Thambugala KM et al. 2018 – Towards a natural classification and backbone tree for Graphostromataceae, Hypoxylaceae, Lopadostomataceae and Xylariaceae. Fungal Diversity 88, 1–65.
Last update: 04 August 2021