Dothidea sambuci (Pers.) Fr., Syst. mycol. (Lundae) 2(2): 551 (1823). Fig. 28

≡ Sphaeria sambuci Pers., Syn. meth. fung. (Göttingen) 1: 14 (1801).

MycoBank number: MB 163394; Index Fungorum number: IF 163394; Facesoffungi number: FoF 00067.

Saprobic on dead stems. Sexual state: Ascostromata 700–1000 × 200–310 μm (x̄ = 900 ×  260 μm, n = 5), black, erumpent through the outer layer of the host tissue, to near superficial, solitary or scattered, globose to subglobose, coriaceous, multiloculate, with 8–15 locules, cells of ascostromata composed of several layers of dark brown cells of textura angularis. Locules 80–120 × 65–90 μm (x̄ = 95 ×  70 μm, n = 20), globose to subglobose, broadly or narrowly conical, with individual ostioles. Ostiole usually widely porate, with well-developed neck, ostiolar canal filled with a tissue of hyaline cells. Peridium of locules 28–41 μm (x̄ = 35 μm, n = 15), comprising 1–2 layers of thick-walled, lightly pigmented, small cells of textura angularis. Hamathecium lacking pseudoparaphyses. Asci 70–80 × 12–15 μm (x̄ = 73.5 × 13.5 μm, n = 10), eight-spored, bitunicate, fissitunicate, clavate to subcylindrical, thickened with a short broad pedicel and rounded at apex, with a clear ocular chamber. Ascospores 17–20 × 5–6.5 μm (x̄ = 17.5 × 5.5 μm, n = 20), uniseriate, partially overlapping, hyaline to light brown when immature, becoming brown to chestnut brown when mature, 1-septate, constricted at the septum, ellipsoidal with broadly rounded ends, smooth-walled, thick-walled, lacking a sheath. Asexual state: Unknown.

Material examined – Austria, Steiermark (Styria) Grazer Bergland, on Sambucus nigra (Adoxaceae), leg D. Baloch 4 October 2002 det. C. Scheuer (GZU 78–2002, epitype).

Notes – As the type specimen is not available, Shoemaker & Hambleton (2005) introduced an epitype specimen for D. sambuci from Sambucus nigra (Adoxaceae) in Austria. There is no identified asexual morph for D. sambuci. According to phylogenetic analysis by Thambugala et al. (2014a), D. sambuci groups with D. insculpta and this was confirmed in our study.

Figure 1. Dothidea sambuci (GZU 78-2002, epitype). a, b Ascostromata on the host substrate. c, d Section through ascostroma showing the arrangement of locules. e Close-up of the locules. f, g Asci in cotton blue reagent. Bearing eight ascospores. h–k Ascospores in cotton blue reagent. Scale bars: b = 1000 μm, c, d = 500 μm, e = 100 μm, f–k = 10 μm.