Coryneum umbonatum Nees, Syst. Pilze (Wu¨rzburg): 34 (1816).
= Pseudovalsa lanciformis (Fr.) Ces. & De Not., Comm. Soc. crittog. Ital. 1(4): 206 (1863)
= Pseudovalsa longipes (Tul.) Sacc., Michelia 1(no. 5):463 (1879)
Saprobic on twigs and stems of overwintered plants. Sexual morph: Stromata solitary, erumpent, comprising pseudoparenchymatous cells. Ectostromatic disc well or poorly developed, brown to black, comprising small cells of textura prismatica. Ascomata 510–525 × 285–300 µm (x̅ = 520 × 290 µm, n = 20), perithecial, immersed, aggregated, globose to subglobose, coriaceous, brown to black, papillate, ostiolate. Papilla 250 9 150 µm, upright, central, broad, sometimes converging. Peridium 10–15 lm (x̅ = 12 µm, n = 20), comprising outer, thick-walled, brown cells of textura angularis and inner, thick-walled, hyaline, compressed cells of textura angularis. Hamathecium comprising broad, cellular, septate paraphyses. Asci 80–95 × 16–18 µm, (x̅ = 92 × 17 µm, n = 20), 8-pored, unitunicate, ellipsoid to cylindrical, thin-walled, stalk pedicellate, apex rounded, with J- apical ring. Ascospores 20–30 × 8–15 µm, (x̅ = 25 × 10 µm, n = 20), overlapping uniseriate to biseriate, hyaline or initially hyaline, brown at maturity, ellipsoid, fusoid or elongate, one to several septate, often distoseptate, end cells pale brown or hyaline, straight or curved. Asexual morph: Conidiomata 450 × 700 µm, acervular, solitary, erumpent through the outer periderm layers of host scattered, surface tissues above slightly domed. Stromatic pseudoparenchyma layer 30–35 µm, (x̅ = 34 µm, n = 20), composed of thin-walled, vertically arranged, dark brown cells of textura epidermis. Conidiophores 20–30 × 3–6 lm (x̅ = 23 × 3.2 µm, n = 20), branched at the base, cylindrical, septate, hyaline at the top, pale brown at the base. Conidiogenous cells 40 × 3.6 µm, formed from the apical cell of the conidiophore, annellidic, cylindrical, hyaline. Conidia 35–45 × 8–10 µm (x̅ = 40 × 9 µm, n = 25), curved, broadly fusiform to fusiform-cylindrical or clavate (rather variable in form), dark brown, smooth-walled, distoseptate with 4–6 septa, the apical and basal cell darker than other cells, apical cell with a hyaline tip.
Material examined: USA, Maryland, Beltsville, Narragansett Pkwy, on stem of Betula sp., 07 June 2002, Vasilyeva, Larissa BPI 871006A (sexual morph); UK, Devon, Slapton, near Kingsbridge, Slapton, Ley National Nature Reserve, site J1, on twigs of Quercus petraea, 11 May 1994, B. C. Sutton, IMI 362542 (asexual morph).
Notes: Coryneum comprises mostly pathogenic and fewer saprobic species. Pathogenic species form cankers, dieback in shoots and twigs. Asexual morph of Coryneum is common in nature and is mostly found as a pathogen.
Fig. Coryneum umbonatum (BPI 871006A and IMI 362542). a Herbarium packet. b Herbarium specimen. c Stromata on substrate. d Transverse section of stroma. e–g Asci. h Peridium. i–j Ascospores. k Packet of the herbarium and specimen. l Herbarium specimen. m Conidiomata on substrate. n Cross section of conidiomata. o Conidia attached to conidiophore. p, q Conidia. Scale bars: c = 1 mm, d = 100 µm, e–h = 20 µm, i–j = 10 µm, m = 500 µm, e = 100 µm, o–q = 10 µm.