Capnodium paracoartatum Q. Tian, W.J. Li & K.D. Hyde, sp. nov.
Etymology: Referring to its morphology similar to C. coartatum, but phylogeny is distinct.
Dothideomycetes, Dothideomycetidae, Capnodiales, Capnodiaceae
Saprobic on sugary exudates from insects growing on the surface of living leaves. Thallus composed of abundant mycelium, growing over the surface of the plant, brown to pale brown, sub-cylindrical, irregularly branched, septate, constricted at the septa, produced numerous pycnidia on the surface of hyphal cells (2–7 μm wide).
Sexual morph: see Chomnunti (2011). Asexual morph: Conidiomata 200–300 × 40–50 μm, brown to dark brown, pycnidial, solitary to gregarious, superficial, flask-shaped to elongated, with a long tapered rostrate apex, lacking basal sterile stalk, unilocular, glabrous. Ostiole apex 40–80 × 10–17 μm, circular, apical, centrally located, surrounded by hyaline hyphae. Stalk and pycnidial wall composed of thick-walled, dark brown cells of textura porrecta to textura angularis at the base and lower half, becoming pale brown, thin-walled, parallel columns, longitudinally elongated pseudoparenchyma toward rostrate apex region. Conidiophores not observed. Conidiogenous cells not observed. Conidia 4–9 × 2–4 μm (= 6 × 3 μm, n=20), hyaline, ellipsoid to cylindrical, rounded at both ends, or occasionally tapered at the base, unicellular, smooth-walled, eguttulate.
Material examined: Thailand, Chiang Rai province, Mae Fah Luang University campus, on living leaves of Ficus sp. (Moraceae), 15 March 2014, Qing Tian, MFU07 (MFLU 19-2888, holotype), ex-type living culture MFLUCC 14-0282.
Notes: Capnodium paracoartatum is similar to C. coartatum in possessing flask-shaped to elongated pycnidia with a long tapered rostrate apex lacking a basal sterile stalk. Capnodium paracoartatum is distinguished from C. coartatum by its conidial size. However, it should be noted that conidial size alone is an inefficient character to delineate Capnodium species, because C. paracoartatum and C. coffeicola share similar conidial size (av. 6 μm long). Capnodium paracoartatum differs from C. coffeicola and C. gardeniarum in lacking a basal stalk. Phylogenetically, C. paracoartatum is distinct from other Capnodium species.
Capnodium paracoartatum (MFLU 19-2888, holotype) a, b Sooty mould on the surface of host plant. c, d Appearance of dark brown conidiomata on the host surface. e, h–j Slide view of stalked pycnidia. f Sterile mycelium. g Rostrate apex. l–m Ostiole surround by hyaline hyphae. n Conidia. o Germinating conidium. p, q Culture on MEA. Scale bars c–d = 100 μm, e = 50 μm, f–k = 20 μm, l–m, o = 10 μm, n= 5 μm.
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.