Xenomassariosphaeria rosae Jayasiri, Camporesi & K.D. Hyde, in Wanasinghe et al., Fungal Diversity: 10.1007/s13225-018-0395-7,  (2018)
Index Fungorum number: IF 554069; Facesofungi number: FoF 03849
Etymology: Reference to host genus Rosa.
Holotype: MFLU 15-1073.
Synonymy: Massariosphaeria roumeguerei (Sacc.) Leuchtm. [as ‘roumegueri’], Sydowia 37: 173 (1984)
Saprobic on Rosa canina. Sexual morph: Ascomata 200–230 μm high, 240–290 μm diam., scattered, gregarious semi-immersed to erumpent through host tissue, small black dots on the host surface, uniloculate, globose to subglobose, with papillate ostioles. Peridium 35–40 μm wide, thick-walled, of unequal thickness, composed of 6–8 layers, hyaline inner layers to brown outer layer, pseudoparenchymatous cells, arranged in a textura angularis to textura globulosa. Hamathecium composed of numerous, 1.5–2 μm wide, filamentous, cellular pseudoparaphyses, with distinct septa, embedded in mucilaginous matrix. Asci (70–)90–110 μm high, 13–18 μm diam (x̄ = 95 × 16 μm, n = 20), 8-spored, bitunicate, fissitunicate, broadly cylindrical to cylindric clavate, subsessile to short pedicellate, apical rounded with well-developed ocular chamber. Ascospores 34–38 × 5–7 μm (x̄ = 36 × 6 μm), overlapping 1–2 seriate, fusiform, asymmetric, hyaline to brown, 6–7-septate, slightly curved, constricted at the septa, thick–walled with sheath. Asexual morph: Undetermined.
Culture characters: Colonies grow on MEA, reaching 2 cm diam after 2 weeks at 18 °C, later with dense mycelium, circular, smooth, irregular margin, off white to pink after 2 weeks, reverse pink to red layers, flat on the surface, with aerial mycelium. Hyphae septate, branched, hyaline, thin-walled, produce pink pigment to the culture.
Material examined: ITALY, Province of Forlı`-Cesena [FC], Converselle, Castrocaro Terme e Terra del Sole, on dead aerial spines of Rosa canina L. (Rosaceae), 3 December 2014, Erio Camporesi IT 2274 (MFLU 15-0179 holotype), ex-type living culture, MFLUCC 15-0179.
GenBank Numbers: LSU: MG829092, SSU: MG829192.
Notes: In this study we introduced a new species accommodated in the family Paradictyoarthriniaceae and genus Xenomassariosphaeria. Xenomassariosphaeria rosae clades with Massariosphaeria roumeguerei (CBS 612.86) with high statistical support (100% ML and 1.00 BYPP). However, Massariosphaeria roumeguerei is not related to any type material and it was introduced based on morphological similarities to Massariosphaeria roumeguerei (Wang et al. 2007). In this study, we synonymise Massariosphaeria roumeguerei under Xenomassariosphaeria rosae.