Dendrostoma creticum Voglmayr & Jaklitsch

Jaklitsch, Walter M. & Voglmayr, Hermann, 2019, European species of Dendrostoma (Diaporthales), MycoKeys 59, pp. 1-26 : 1

Dendrostoma creticum Voglmayr & Jaklitsch sp. nov. Figure 7

Diagnosis.

Dendrostoma creticum is recognized by long, subacicular ascospores.

Holotype.

Greece, Crete, near Askifou, 35°17'47"N, 24°12'33"E, on twigs of Quercus coccifera , soc. Cytospora ( Valsa morph) sp., 6 June 2015, H. Voglmayr & W. Jaklitsch (WU 37031; ex-type culture CBS 145802 = D124)

Etymology.

Creticum , referring to its occurrence, Crete.

Description.

Sexual morph: pseudostromata 0.6-1.6 mm in their widest dimension in cross section, pulvinate, circular, elliptic or irregular in outline, scattered, gregarious to confluent up to 4 mm length, causing small bumps in the bark, splitting the periderm. Ectostromatic discs 0.25-1.4 mm in their widest dimension, medium to dark brown, flat or convex, surrounded by bark flaps. Ostioles 1-7 per disc, (31 –)55–102(– 135) µm (n = 40) in diameter at the rounded tip, dark brown to black, bluntly conical, plane with the disc or slightly prominent. Entostroma pale bark coloured, mottled. Perithecia (245 –)320–445(– 495) µm (n = 30) in diameter, depressed-subglobose, collapsing upward; peridium ca 10-50 µm thick, a dark brown textura angularis in face view, in section outside of dark brown textura angularis to strongly compressed cells (4 –)7–14(– 18) µm (n = 30) in diameter, inside of strongly compressed and elongated hyaline cells. Paraphyses absent at maturity. Asci (66 –)71–85(– 94) × (8.8 –)9.5–11.2(– 12.3) µm (n = 44), narrowly clavate to subfusoid, floating freely in the centre, containing 8 bi- to triseriate ascospores. Ascospores (26 –)33–45.5(– 52) × (2.7 –)3–3.7(– 4.6) µm, l/w (6.8 –)9.8–14.3(– 17.5) (n = 40), 2-celled, slightly constricted at the median or often distinctly eccentric septum, oblong, straight to curved, with the upper cell often slightly wider than the lower, hyaline, multiguttulate, smooth, with or without a hyaline subconical appendage (1.4 –)1.5–2.3(– 3.2) × (0.6 –)0.9–1.3(– 1.5) µm (n = 25) at each end.

Asexual morph unknown.

Culture characteristics.

On CMD at 16 °C in the dark colony circular to irregular, dense, white, partly covered by short, white aerial hyphae, zonate, soon turning dark brown to black with pale apricot spots and margin and apricot to orange pigment diffusing into agar, reverse dark brown with orange margin.

Notes.

Dendrostoma creticum is similar to the closely related D. istriacum but differs by distinctly longer ascospores, darker ectostromatic discs and a different host species.

Figures

Figure 7. Dendrostoma creticum (WU 37031 = D 124). a, b, d Ectostromatic discs and ostioles in face view c pseudostroma in cross section e peridium in cross section in 3 % KOH f-i asci j-r ascospores. Scale bars: 200 µm (a, b, d), 500 µm (c), 10 µm (e-r).