Pyrispora castaneae – Facesoffungi number: FoF14481

Pyrispora castaneae C.M. Tian & N. Jiang, sp. nov.

MycoBank number: MB 838317; Index Fungorum number: IF 838317; Facesoffungi number: FoF14481;

Etymology—named for the host genus, Castanea.

Holotype—BJFC-S1798

Pathogenic or saprobic on Castanea mollissima leaves. Sexual morph: Ascomata 80–200 µm diam., semi-immersed, aggregated, globose to pulvinate, black, single ostiolate. Ostioles 30–75 µm, diam., single, dark grey to black. Paraphyses deliquescent. Asci (41–)44.5–52(–58) × (7–)8.5–10.5(–11) µm, cylindrical to clavate, 8-spored, bi-seriate, with a distinct apical ring. Ascospores (11.4–)12.2–14.5(–14.9)  ×  (4.3–)4.4–4.9(–5.2) µm (x = 13.3 × 4.7 µm, n = 50), L/W = (2.2–)2.5–3(–3.2) (x = 2.9, n = 50), aseptate, hyaline, smooth, fusoid, multiguttulate, straight to slight curved. Asexual morph: Conidiomata 60–250 µm diam., pycnidial, aggregated, globose to subglobose, black, single ostiolate. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 4–7.5 2–3.5 µm, pyriform base with long neck, necks up to 45 µm, hyaline, phiailidic, unbranched, straight. Conidia (10.4–)11.7–13(–13.9) × (4.1–)4.4–4.9(–5.5) µm (x = 12.3 × 4.5 µm, n = 50), L/W =(2.2–)2.5–3.2(–3.4) (x = 2.8, n = 50), aseptate, hyaline, smooth, ellipsoidal, multiguttulate (Figures 24 and 25).

Culture characteristics—Colonies on PDA reaching up to 60 mm in 7 days, flat, white, with cottony aerial mycelium and fringed margin; reverse pale yellowish.

Material examined—CHINA, Sichuan Province, Yaan City, Shimian County, 29◦13′31′′ N, 102◦21′27′′ E, alt. 978 m, on leaf spots of Castanea mollissima, 10 September 2020, N. Jiang (BJFC-S1798, holotype; ex-type living culture, CFCC 54349 = SM17); ibid. (BJFC-S1799, living culture, CFCC 54350 = SM20); ibid. (BJFC-S1800, living culture, SM28); ibid. (BJFC- S1801, living culture, CFCC 54351 = SM29); ibid. (BJFC-S1802, living culture, SM30); ibid. (BJFC-S1803, living culture, SM31); Hunan Province, Xiangtan City, 27◦48′51′′ N, 112◦71′42′′ E, alt. 85 m, on leaf spots of Castanea mollissima, 9 November 2020, C.M. Tian & N. Jiang (living culture, CFCC 54578 = XT01).

Figure 24. Pyrispora castaneae (BJFC-S1800). (A,B) Ascomata on the diseased leaves of Castanea mollissima; (C–F) Asci and ascospores. Scale bars: (C–F) = 10 µm.

Figure 25. Pyrispora castaneae (BJFC-S1798). (A,B) Conidiomata on the diseased leaves of Castanea mollissima; (C–E) Conidiogenous cells giving rise to conidia; (F) Conidia. Scale bars: (C–F) = 10 µm.