Anthostomella rubicola (Speg.) Sacc. & Trotter, Syll. fung. (Abellini) 22: 100 (1913)

Index Fungorum number: IF 199890; Facesoffungi number: FoF 00320

Saprobic on wood. Sexual morph: Ascomata immersed, solitary or aggregated into clusters, appearing as blackened slightly raised conical areas, in cross sections 250–300 diam. × 300 µm high ( = 280 × 300 µm, n = 10), globose, with a central black ostiolar dot, disc-like, black, clypeus present comprising host cells and intracellular fungal hyphae, surrounded by carbonaceous tissues, 65–85 µm diam at base, 80 µm high ( = 72 × 80 µm, n = 10). Peridium 25–30 µm diam. ( = 27 µm, n = 10), with few compressed cell layers, outwardly comprising thick-walled, yellowish brown cells of textura irregularis and inwardly comprising hyaline cells of textura angularis. Paraphyses 6.5 µm diam., few, filamentous, aseptate. Asci 120–175 × 6.5–9 µm ( = 155 × 8 µm, n = 30), 8-spored, unitunicate, cylindrical, short-pedicellate, apically rounded, with a wedge-shaped, J+, apical apparatus, 3–5 × 4–4.5 µm ( = 4.1 × 4.4 µm, n = 30). Ascospores 25–32 × 5.5–8 µm ( = 28 × 6 µm, n = 40), overlapping uniseriate or biseriate, ellipsoidal, one end tapered and pointed, in asci ascospores always hyaline, unicellular with rostrate hyaline, dwarf cell at base, 4–6.5 µm long ( = 5.3 µm, n = 40), smooth-walled, larger cell rarely dark brown or mostly hyaline. Asexual morph: undetermined.

Culture characteristicsColonies on Difco OA at 25–27 oC reaching 7 cm in 4 weeks, at first whitish, felty, azonate, with diffuse grey colour margins, reverse turning citrine (13).

Specimens examined – ITALY, Province of Forlì-Cesena, Santa Marina in Particeto – Predappio, on Rubus ulmifolius Schott. (Rosaceae), 5 January 2014, E. Camporesi IT1630 (MFLU 14-0234, reference specimen designated here), living cultures, MFLUCC 14–0175; ibid, 5 January 2014, E. Camporesi IT1630 (PDD).

GenBank Accession numbers – ITS: KP297407, RPB2: KP340535, ß-tubulin: KP406618, LSU: KP340548.

Notes – Anthostomella rubicola is distinct from A. appendiculosa (Berk. & Broome) Sacc. as the latter has rhomboid ascomata with a lower and oblique ostiolar canal, while A. rubicola has conical ascomata with a central ostiolar canal. Ascospores in A. appendiculosa are larger and become brown in the asci with a cordate dwarf cell and a straight germ slit, while those in A. rubicola remain hyaline in the asci and brown spores are rarely observed. The dwarf cell is rostrate, and ascospores lack a germ slit. Lu and Hyde (2000b) observed the holotype material from LPS together with many other types and non–types that represent A. rubicola. The characters from this specimen are similar to A. rubicola as per the description from the holotype material (Lu and Hyde 2000b). It was not possible to loan the type material from LPS herbaria for morphological observation and we are not aware of any isolates of the species. Thus we use a fresh collection from Italy that we isolated in culture to designate as a reference specimen rather than an epitype because our material was collected from Italy while the holotype was collected from Chile (sensu Ariyawansa et al. 2014). We also deposited sequences in GenBank to stabilize the application of the name.

Fig 1: Anthostomella rubicola (MFLU 14-0234) a. Habit on wood b. Ascoma in wood c. Ascoma in side view d. Cross section of an ascoma e. Peridium f. Paraphyses g–i. Asci in water j. Asci in Melzer’s reagent with cylindrical, J+, apical apparatus k–n. Immature asci in water. Scale bars: a = 1000 µm, b = 200 µm, c = 100 µm, d = 200 µm, e = 30 µm, f–j = 10 µm, k–n = 20 µm.