Leptosphaeria cirsii Jayasiri, Camporesi & K.D. Hyde, in Hyde et al., Fungal Diversity 80: 55 (2016)
Index Fungorum number: IF 552155; Facesofungi number: FoF 02220
Etymology: The specific epithet circii is based on the host genus from which the taxon was collected.
Holotype: MFLU 15-1072
Saprobic on dead stem of Cirsium sp. Sexual morph: Ascomata 285–315 × 335–360 μm (x̄ = 304 × 347 μm, n = 10), solitary or scattered, superficial, globose to subglobose, broadly or narrowly conical, coriaceous, smoothwalled, ostiolate. Ostiole usually papillate, darkened at the base. Peridium 22–27 μm (x̄ = 24 μm, n = 20) wide, comprising two types of cells, outer cells of 1–2 layers of heavily pigmented cells of textura angularis, inner layer composed of small, light brown to hyaline cells of textura angularis. Hamathecium of septate, long, hyaline, cellular pseudoparaphyses, between and above the asci. Asci 75–110 × 10–12 μm (x̄ = 95 × 11 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindro-clavate, with a short, broad pedicel, thickened and rounded at the apex, with a distinct ocular. Ascospores 19–22 × 4–4.5 μm (x̄ = 20 × 4.2 μm, n = 40), overlapping uni-seriate, hyaline to light brown when immature, becoming brown to chestnut brown when mature, ellipsoidal with narrowly rounded ends, 3-septate, smooth-walled with mucilaginous sheath. Asexual morph: Coelomycetous on MEA. Conidiomata 150–200 × 195–220 μm (x̄ = 190 × 205 μm, n = 10), pycnidial, superficial, immersed in media, globose to subglobose, black, without an ostiole. Conidiomata wall 15–25 μm wide, composed cells of textura angularis in multiple layers, pale yellowish-brown, remaining hyaline in inner layer. Conidiogenous cells 2–5 × 2–4 μm (x̄ = 3.5 × 2.5 μm, n = 30), enteroblastic, phialidic, determinate integrated, subglobose to short conical. Conidia 3–6 × 1–3 μm (x̄ = 3.8 × 1.5 μm, n = 50), hyaline, aseptate, oblong to cylindrical, thin-walled, smooth, guttulate, rounded at both ends.
Culture characteristics: Colonies on MEA 60 mm diam. after 4 weeks at 18 °C, white on the top and reverse, reverse yellow to brown near the middle, some area dense, circular, regular margin, without diffusible pigments.
Material examined: ITALY, Province of Trento [TN], near Vermiglio—Val di Sole, on dead stem of Cirsium sp. (Asteraceae), 9 August 2014, E. Camporesi IT 2044, (MFLU 15-1072, holotype); (KUN, isotype); ex-type living culture, MFLUCC 14-1170, KUNCC.
Notes: Leptosphaeria cirsii is introduced here based on both morphology and phylogeny. Leptosphaeria cirsii is typical of Leptosphaeria in having a peridium of plectenchymatous cells and reddish to yellowish-brown, fusoid, 3-septate ascospores. Phylogenetically, L. cirsii clusters with L. cichorium with relatively moderate support (61 % ML) and also shares affinities to L. italica. Morphologically L. cirsii is similar to L. cichorium in having similar asci, ascospores, cellular pseudoparaphyses and asexual state morphology, but differs in having, superficial, globose to subglobose, broadly or narrowly conical ascomata and ascospores with a mucilaginous sheath (Ariyawansa et al. 2015). Leptosphaeria cirsii resembles L. italica but differs as L. cirsii has long and narrow ascospores and lacks an ostiolar canal (Dayarathne et al. 2015) (Hyde et al. 2016).