Chaetosphaeria garethjonesii – Facesoffungi number: FOF 02658

Chaetosphaeria garethjonesii R.H. Perera, Maharachch. & K.D. Hyde

Index Fungorum number: IF552536; Facesof fungi number: FoF02958

Etymology – In honor of E.B.G. Jones for his work on marine fungi.

Saprobic on a Fabaceae seed pod. Sexual morph: Ascomata brown to dark brown, not collapsing when dry, ovoid to broadly obpyriform, 191–250 μm diameter, 240–257 μm high, superficial, scattered to gregarious, setose, slightly papillate. Setae scattered over entire ascomata, dark brown, stiff, pointed, 38–47 μm. Peridium cells 21–59 μm thick, with cells textura globosa in surface view, 3-layered in longitudinal section, with inner layer 2–3 cells thick, composed of light brown to hyaline elongate cells, with middle layer 4–6 cells thick, composed of small, brown to dark brown, elongate to polygonal cells, with outer layer 2–3 cells thick, composed of large isodiametric to polygonal, brown cells. Paraphyses 5.6–8.6 μm wide, of variable length, simple, sparse, hyaline, unbranched, tapering towards the apex, septate. Asci 120–152×10.7–13.3 (x̅ =137×12 μm, n = 20) μm, 8-spored, unitunicate, cylindrical, pedicellate, with rounded apex, with a thin, J-, apical ring. Ascospores 63.3–75×2.3–3.7 (x̅ = 69.5×3.1 μm, n = 30) μm, fasciculate, straight to gently curved, with rounded ends, slightly tapering to base, 7-septate, sometimes slightly constricted at septa, hyaline, smooth-walled, without a gelatinous sheath. Asexual morph: Undetermined.

Culture characters – Twenty-one day old colonies on MEA 60–76 mm diameter, flat, lacking aerial mycelium, margins effuse, dark brown at margins, gray to white at the center from above, reverse dark brown.

Material examined – THAILAND, Chiang Mai Province, on a Fabaceae seed pod, 19 July 2015, R.H. Perera, RHP 115 (MFLU 16-1019, holotype), ex-type living culture, MFLUCC 15-1012.

Notes – Chaetosphaeria garethjonesii is a distinct species in the genus, as supported by molecular and morphological characters. In the phylogenetic tree, C. garethjonesii is sister to C. albida T.J. Atk. et al. and C. bombycina T.J. Atk. et al.. Chaetosphaeria garethjonesii differs from C. albida and C. bombycina in ascomatal morphology. Chaetosphaeria albida and C. bombycina are characterized by almost white or light fawn-grey, translucent or reflective ascomatal with walls lacking setae, while C. garethjonesii has brown to dark brown ascomata with setose, rough walls (Atkinson et al. 2007). Ascospore septation in C. albida is less than in C. bombycina (7 vs. 11; Atkinson et al. 2007).