Biscogniauxia effusa Q.R. Li, J.C. Kang & K.D.Hyde.
Index Fungorum number: IF551308; Facesoffungi number: FoF: 00875; Fig. 1
Etymology – In reference to the effuse stromata.
Holotype – GZUH0122

Saprobic on dead bark. Sexual morph: Stromata more than 5 cm long and 3 cm diam., widely effuse, crust – like, flat or slightly undulate, black, bipartite, confluent, without raised margins, ascomatal mounds, with black ostioles. Ascomata 180 – 230 μm high, 320 – 450 μm diam. (x̄ = 210 × 390 μm, n = 10), solitary, obovoid, black, carbonaceous, immersed, encasing a single ascoma, in vertical section, globose to subglobose, ostiolate. Peridium 40 – 60 μm wide, black. Paraphyses not seen. Asci spore – bearing part 170 – 200 × 12 – 14 μm (x̄ = 190 × 13 μm, n = 30), 8 – spored, unitunicate, cylindrical, stipes 25 – 30 μm long, apically rounded, with a J+, tubular, 7 – 8 μm high, 5 – 6 μm wide apical apparatus. Ascospores 25 – 31 × 8 – 10 μm (x̄ = 28 × 9 μm, n = 30), uniseriate, light brown, unicellular, equilateral ellipsoidal, with broadly rounded ends, smooth-walled, with a full length, straight, germ slit. Asexual morph: Undetermined.

Culture characteristics – Colonies growing slowly on PDA, reaching 2 cm diam. after 2 weeks at 25 °C, brown, black in reverse side, cottony, flat, low, dense, with slightly wavy margin.

Material examined – CHINA, Hainan Province, Sanya City, Jianfengling National Nature Reserve, on dead bark of unknown plant, March, 2015, Q.R. Li (GZUH0122, holotype); ex-type living culture, GZUCC0122.

Notes – Biscogniauxia effusa has flattened stromata and is similar to B. atropunctata (Schwein.: Fr.) Pouzar. and B. weldenii (J.D. Rogers) Whalley&Læssøe in ascospore size (Ju et al. 1998). Biscogniauxia atropunctata differs in having 16 – 22 × 7.5 – 11 μm, ellipsoid ascospores, with straight germ slits, and shorter 150 – 170 μm asci with a J+, discoid, apical apparatus (Ju et al. 1998). Biscogniauxia weldenii differs in having 25 – 28 × 9.5 – 10.5 μm ascospores ornamented with striations and with an appendage (Ju et al. 1998). Biscogniauxia effusa groups with B. marginata (Fr.) Pouzar and B. arima F.San Martín et al. and forms a well – supported monophyletic clade in the Xylariaceae with 93 % bootstrap support.

Fig. 1 Biscogniauxia effusa (holotype) a Herbarium sample b Stroma on the surface of host c Surface of stroma cut away to reveal ascomata d, e Ascus apex with a J+, apical apparatus f – i Asci with ascospores (stained in Melzer’s reagent). j – m Ascospores. Scale bars: b, c = 200 μm, d – m = 10 μm.