Index Fungorum Number: 558265

Etymology:— The specific epithet refers to the feature of the capitate stromata.

Holotype:— HKAS 55588

Parasitic in an unidentified host buried in the upper 1 cm of soil, forming brown to dark stromata. Sexual morph: Ascomata 8–13 cm long, 5–10 mm wide, stromatic, brown to olive when fresh, dark when dry, tough, capitate, mostly solitary, stipitate, inside hollow when mature. Stipe 8–12 × 0.5–0.7 cm, cylindrical, yellow to brown when fresh, dark brown when dry, with green scales on the surface when fresh, with dark furfuraceous when dry, fibrous, hollow, with stromata on the top. Fertile head 8-10 mm in diam, hemispherical, minutely mammilate, bracken green to dark olive when fresh, dark when dry, distinctly separated from the stipe, tough, solitary, with a cortex of closely interwoven hyaline hyphae pseudoparenchymatous in section. Perithecia 500–600 × 340–420 μm (x = 560 × 380 µm, n = 30), subglobose to ovoid, immersed in stroma with slightly protruding ostiolar papilla. Ostiole lined with paraphyses. Peridium 20–25 µm (x = 22 µm, n = 60) wide, of brown pigmented cells of textura porrecta to paler textura prismatica. Asci 320–400 × 10–15 um (x = 360 × 13 µm, n = 60), 8-spored, unitunicate, narrow cylindrical, hyaline, with thick apex. Apical cap 5.5–7.5 × 5–7.5μm (x = 6.5 × 6 µm, n = 60) μm diam, hyaline. Ascospores as long as asci, filiform, hyaline break into secondary spores. Secondary spores 25–35 × 3–4.5 μm (x = 30 × 3.8 µm, n = 60), cylindrical to fusoid with truncated ends, smooth, hyaline, with or without septa. Asexual morph: Undetermined.

Material examined:— CHINA, Yunnan Province, Lijiang City, Laojun Mountain. 15 July 2008, Yun Ting Huang (HKAS 55588, holotype), (GZU A-77, i sotype).

LSU: MW798786 MW 7987877, SSU MW 798784 MW 798785, ITS MW798788 MW 798789 (Supplementary Table 1)

Notes:—We identified this species after we inspected the unidentified specimens in the Herbarium of Kunming Institute of Botany, Chinese Academy of Sciences (HKAS). According to morphology and phylogenetic analysis (Fig. 7), the new species Tolypocladium cucullae is close to T. capitatum, T. delicatistipitatum, T. fumosum and T. longisegmentatum. Tolypocladium cucullae is distinct from T. capitatum by producing hollow, furfuraceous stipe, smaller perithecia and smaller asci, while T. capitatum produces tough stipe, bigger perithecia and longer asci (Mains 1957, Table 3). Tolypocladium cucullae is distinct from T. fumosum in having larger and brown to olive when fresh, dark when dry stromata; larger, hemispherical and bracken green to dark olive when fresh, dark when dry fertile head; smaller perithecia; longer and cylindrical to fusoid secondary spores. Tolypocladium fumosum has smaller, pale chalcedony yellow at the base to dark gull grey at the apex stromata; ellipsoidal when young and capitate when mature fertile head; larger perithecia; shorter and cylindrical to cubic secondary spores. The phylogenetic tree also supports that T. cucullae is distinct from T. capitatum and T. fumosum (Fig. 7).

The morpho-characters of T. cucullae are similar to T. delicatistipitatum, but the latter has no DNA sequence data. Both of them formed stipitate stromata, subglobose to ovoid perithecia, cylindrical asci and cylindrical secondary spores with truncate ends. Tolypocladium cucullae is different from Tolypocladium delicatistipitatum in producing stromata with a hemispherical, dark (when dry) fertile part, with a thinner (5.5–6 μm in diam) apical cap and longer (25–35 μm long) secondary spores, while T. delicatistipitatum produces stromata with a spherical or oval fertile part, a thicker (8 μm in diam) apical cap and shorter (18–28 μm long) secondary ascospores.

Molecular data have been supplemented by four strains, including OSC 110992 (Sung et al. 2007), HMJAU6903 (Yan & Bau 2014), MHHNU 8699 (Chen & Zhang 2019) and 2731.S (Stensrud et al. 2005). Furthermore, HMJAU6903 (Yan & Bau 2014) and MHHNU 8699 (Chen & Zhang 2019) were reported molecular data with descriptions and illustrations among these four strains. Tolypocladium cucullae is distinct from T. longisegmentatum (DAOM 137162, Ginns 1988; HMJAU6903, Yan & Bau 2014; MHHNU 8699, Chen & Zhang 2019) in having a hemispherical fertile head, brown perithecia and shorter secondary spores (Table 3). Molecular data indicated that the new species has 31 bp in ITS that differ from HMJAU 6903, 36 bp in ITS that is different from MHHNU 8699, 38 bp in ITS is different from 2731.S, 26 bp in LSU that are different from OSC 110992. In conclusion, we propose T. cucullae as a new species.