Roussoella verrucispora Kaz. Tanaka, J. K. Liu & K. D. Hyde. 2014, sp. nov.
Creators: name: Liu, Jian-Kui
name: Phookamsak, Rungtiwa
name: Dai, Dong-Qin
name: Tanaka, Kazuaki
name: Jones, Gareth
name: Xu, Jian-Chu
name: Chukeatirote, Ekachai
name: Hyde, Kevin D.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Dothideomycetes
Pleosporales
Roussoellaceae
Roussoella
Roussoella verrucispora

description: Roussoella verrucispora Kaz. Tanaka, J.K. Liu & K.D. Hyde., sp. nov. FIG. 13   
Index Fungorum: IF550667  
 Etymology. Named for the verrucose ascospores.   
 Saprobic on decaying bamboo culms. Ascostromata 1.3–4.8 mm diam., semi-immersed or immersed under a clypeus, raised, visible as black, dome-shape areas on host surface, scattered to gregarious. Locules 280–320 µm high, 400–430 µm diam., depressed globose with a flattened base, 2–3 grouped, ostiolate. Beak short papillate, 50–75 µm high, 55–75 µm wide. Peridium 12.5–17.5 µm thick at sides, composed of 4–6 layers of rectangular flattened cells (3.5–18 × 1.5–4.5 µm), surrounded by wedge-shaped stromatic region (210–240 µm wide at sides) composed of polygonal to subglobose cells (3.5–18 × 4–15 µm). Hamathecium comprising 1–2 µm wide, numerous, anastomosing, cellular pseudoparaphyses, branching, rough-walled, and embedded in a gelatinous matrix. Asci 135–160 × 8–10 µm (x = 150 × 9 µm, n = 18), 8-spored, bitunicate, cylindrical, short-stalked (12–20 µm long). Ascospores 18–24.5 × 5.5–7 µm (x = 21.5 × 6.2 µm, n = 50), uniseriate, fusiform to ellipsoidal, 2-celled, constricted at the septum, brown, verrucose wall, covered with irregular longitudinal short striations and surrounded by an entire sheath of 1–5 µm wide.   
 Specimen examined. JAPAN, Aomori, Shimokita, Yagen, on twigs of Sasa kurilensis, 18 Nov 2001, Y . Ooki et al. (holotype HHUF 26988, ex-type living culture CBS 125434).   
 FIGURE. Roussoella thailandica. a. Ascostromata on the bamboo culm; b. Section of ascostroma; c, d. Peridium; e. Pseudoparaphyses; f−j. Asci; k, l. Ascospores with irregular longitudinal striations; m. Geminating ascospore; n, o. Culture characteristics. ─ Scale bars: a = 500 μm; b = 100 μm; c, d = 50 μm; e−m = 10 μm; n, o = 30 mm.   
 FIGURE. Roussoella verrucispora (HHUF 26988). a, b. Ascostromata on host surface; c, d. Section of ascostroma; e. Wedge-shaped stromatic region; f. Peridium; g. Pseudoparaphyses; h, i. Asci; j–p. Ascospores. ─ Scale bars: a, b = 1 mm; c = 500 µm; d = 100 µm; e–i = 20 µm; j–p = 5 µm.   
 Notes: Roussoella verrucispora is similar to R. hysterioides, but the asci and ascospores are considerably smaller (asci 135–160 × 8–10 µm vs. 140–210 × 8–11 µm; ascospores 18–24.5 × 5.5–7 µm vs. 18–34 × 6–8 µm) than those of R. hysterioides (Hyde et al. 1996). In addition, the ornamentation of ascospores in R. verrucispora is verrucose, while those of R. hysterioides are linear and full length. This species was named as “ R. hysterioides ” (HHUF 26988) in Tanaka et al. (2009). Roussoella verrucispora is also morphologically similar to R. japanensis, but differs in having slightly larger asci and ascospores (asci 135–160 × 8–10 µm vs. 107–132 × 8–9.5 µm; ascospores 18–24.5 × 5.5–7 µm vs. 16–22 × 5.5–7 µm). The ascospores of R. verrucispora have verrucose ornamentation, while those of R. japanensis are striate. Phylogenetic analysis also distinguished these species (FIGS. 1, 2).
description: Published as part of Liu, Jian-Kui, Phookamsak, Rungtiwa, Dai, Dong-Qin, Tanaka, Kazuaki, Jones, Gareth, Xu, Jian-Chu, Chukeatirote, Ekachai & Hyde, Kevin D., 2014, Roussoellaceae, a new pleosporalean family to accommodate the genera Neoroussoella gen. nov., Roussoella and Roussoellopsis, pp. 1-33 in Phytotaxa 181 (1) on pages 20-22, DOI: 10.11646/phytotaxa.181.1.1, http://zenodo.org/record/5145667