Aurantioporthe corni (Wehm.) G. Beier & R.A. Blanchette, in Beier, Hokanson, Bates & Blanchette, Mycologia
107(1): 71 (2015).
Illustration: See Beier et al. (2015)
Pathogenic on woody stems. Sexual morph: Ascogenous stromata immersed to semi-immersed, orange, upper region eustromatic to pseudostromatic, lower region pseudostromatic. Ascomata 130–290 × 200–350 µm (x̅ = 235 × 277 µm, n = 20), perithecia, solitary or in groups of 2–4, valsoid to diatrypoid, surrounded by host tissues, globose to subglobose. Neck 100–350 × 100–200 lm at base (x̅ = 217 × 127 µm, n = 20), fuscous black, mature ostiolar necks emerge at stromatal surface having black clypei. Clypeus 95–240 µm wide (x̅ = 166 µm, n = 60). Asci 40–70 × 6–12 µm (x̅ = 54 × 8 µm, n = 60), 8-spored, unitunicate, fusiform to ellipsoidal to clavate, J-, refractive ring present. Ascospores 10–18 × 3–7 µm(x̅ = 13 × 4 µm, n = 50), fusiform to ellipsoidal to pyriform, with a median to submedian, slightly constricted septum, occasionally with additional septa, hyaline. Asexual morph: Conidiomata 145–385 × 180–510 µm(x̅ = 241 × 282 µm, n = 50), separate from ascogenous stromata, orange, immersed to semi-immersed, irregularly subsphaerical to flattened, unilocular, single ostiole, cells near ostiole pseudoparenchymatous. Neck 60–185 × 80–265 µm at base (x̅ = 113 9 155 µm, n = 50), short, wide. Conidiophores 10–15 × 1.5–3 (x̅ = 12 × 2 µm, n = 80), obclavate narrowing to a point, branched, conidiogenous cells phialidic. Conidia 6–10 × 2–4 µm(x̅ = 7 × 3 µm, n = 160), minute, hyaline, fusiform to ellipsoidal, aseptate, exuded as orange droplets (description based on Beier et al. 2015).
Notes: Aurantioporthe is a monotypic genus comprising the type species, A. corni. This fungus is the causative agent of golden cankers on Cornus alternifolia. This species is mainly distributed in USA and Canada. Morphologically, it differs from other genera in Cryphonectriaceae in having ascogenous stromata, immersed to semi-immersed conidiomata and uni-to multi septate ascospores.