Dendrostoma covidicola Samarak. & Jian K. Liu, 2021

Samarakoon, Milan C. & Promputtha, Itthayakorn, 2021, Dendrostoma covidicola sp. nov. (Erythrogloeaceae, Diaporthales) on Fagus sylvatica from Sichuan Province, China, Phytotaxa 483 (2), pp. 85-94 : 89-90

Dendrostoma covidicola Samarak. & Jian K. Liu , sp. nov. ( FIGURE 2 )

MycoBank number: MB838110; Facesoffungi number: FoF 09528

Etymology—the epithet “ covidicola ” referring to the COVID-19 pandemic and as a tribute to the battle against COVID-19

Holotype — HKAS 107013

Saprobic on dead branches of Fagus sylvatica L. ( Fagaceae ). Sexual morph Pseudostromata 1.5–2.6 mm in their widest dimension in cross section, variable, flat subconical or lenticular, in outline circular, elliptic or elongate, scattered, gregarious or confluent, and forming elongate patches, lifting the periderm slightly and often becoming visible as a dark zone on the bark surface, causing bumps in the bark, splitting the periderm. Ectostromatic discs yellowish brown to dark brown, flat, surrounded by bark flaps, first present as a covering layer with ostiolar necks subsequently bursting through it, soon crumbling away. Perithecia 400–530 μm high × 290–425 μm diam. (x = 470 × 362 μm, n = 15), 5–20 per disc, aggregated, depressed subglobose to ellipsoid, with a flattened base. Ostioles eccentric, bluntly conical or cylindrical with black sides and yellowish, or brownish tip, often attenuated to a minute, periphysate. Peridium 13–26 μm (x = 19.4 μm, n =10) thick, textura angularis cells 11.5–19 × 2.4–4 μm (x = 15 × 3.3 μm, n = 20), hyaline, pale olivaceous to brown, thicker peridium near to ostioles. Paraphyses absent at maturity. Asci 45–55 × 8–14 μm (x = 51.5 × 10.8 μm, n = 25), 8-spored, unitunicate, narrowly clavate to subfusoid or oblong, floating freely in the centre, thick-walled at the apex containing a distinct apical ring. Ascospores 11–15 × 2.5–3.5 μm (x = 13.5 × 3.1 μm, n = 30), l/ w 4.3, overlapping uni- or bi-seriate, ellipsoidal to subfusiform, hyaline, 2-celled, constricted at the septum, oblong to inequilaterally ellipsoid, straight to mostly curved, with the upper cell often slightly wider than the lower, broadly rounded at the ends, guttulate (mostly 2 large guttules per cell), smooth, with or without a hyaline, straight or curved filiform appendage 3.4–5.2 μm (x = 4.3 μm, n = 20) long. Asexual morph: Undetermined.

Colony characteristics—on PDA, reaching 20–25 mm diam. after four weeks at 25 °C, dark, circular to irregular, dense, zonate, yellowish green to pale grayish brown from the top view with white margin; dark yellowish green with white margin from lower view.

Material examined— China, Sichuan Province, Chengdu, University of Electronic Science and Technology of China (UESTC) campus (Qingshuihe), on the dead branch of Fagus sylvatica L. ( Fagaceae ), 30 September 2019, MC. Samarakoon, SAMC245 (HKAS 107013, holotype; MFLU 21–0001, isotype), ex-type living cultures GZCC 20–0355 = MFLUCC. Additional sequence: tub MW262895 .

Figures

FIGURE 2. Dendrostoma covidicola (holotype, HKAS 107013) a Host. b,d,e Ascomata on the substrate. c,f Vertical section of pseudostroma. g Peridium. h Vertical section of ostioles. i–p Ascospores. q,r Upper and reverse view of the 2 weeks old colony on PDA respectively. s–x Asci (s,x in Congo Red). Scale bars: d = 1 cm, b,c,e,f = 500 µm, h = 50 µm, s–x = 20 µm, g = 10 µm, i–p = 5 µm.