MycoBank No: MB842287

Holotype: — CHINA, Guizhou Province, Tongren, Fanjingshan Nature Reserve (27°53′44.77″N, 108°43′52.69″E), elev. 989 m, dead branch of Litsea verticillata Hance, 14 October 2020, S. H. Long and Lili Liu FJS19 (GMB0084, holotype, ex-type GMBC0084; KUN-HKAS 122639, isotype).

Saprobic on dead twig of L. verticillata. Sexual morph Subiculum felted, brown, restricted to rim around stromata, evanescent. Stromata 630–735 µm high × 525–700 µm diam. (av. = 679 × 628 µm, n = 20), superficial, scattered to gregarious, solitary, globose, with a conical pointed top, dark, shiny, carbonaceous. Ostioles black, papillate. Ectostroma 80–100 µm thick, black, carbonaceous. Entostroma disappearing at maturity. Perithecia filling entirely the stroma cavity or partly collapsed. Asci 173. 5–241.5 × 18.5–39 µm (av. = 212.5 × 30 µm, n = 30), 8-spored, unitunicate, cylindrical, short pedicellate, apically rounded, with a long J+, barrel-shaped apical apparatus in Melzer’s reagent, 11.5–15.5 µm high, 7–8 µm wide. Ascospores 42–62 × 6.5–12 µm (av. = 55 × 9.3 µm, n = 30), overlapping uniseriate or biseriate, fusiform, ends rounded, hyaline when immature, slight brown to brown at maturity, straight to curved, with a germ slit running the entire length of the spores, entirely surrounded by a thin slimy sheath visible in water and in black ink, lacking appendages. Asexual morph Undetermined.

Culture characteristics: —Ascospores germinated on PDA within 24 hours. Colonies on PDA were white when young, became pale brown, dense, but thinning towards edge, medium dense, white from above, reverse side white at margin, flesh to pale brown at centre. No pigmentation was produced on PDA medium. No conidia were observed on PDA or OA media.

Habitat/Distribution: —Known to inhabit dead wood, Guizhou Province, China.

Etymology: —Refers to its host species, L. verticillata

Other material examined: — CHINA, Guizhou Province, Ya Mu Gou Scenic Area (27°54′42.83″N, 108°42′9.08″E), altitude: 1058 m, dead branch of unidentified plant, 15 October 2020, S. H. Long, FJS45 (GMB0085, KUN-HKAS 122641, living culture GMBC0085).

Additional sequences: —GMB0084 (LSU: OM001207) GMB0085 (LSU: OM001208).

Note: —In the phylogenetic tree (Fig. 1), R. verticillata clustered together with R. tetrastigmae Q.R. Li & J.C. Kang. However, the ascospores of R. verticillata are smaller than those of R. tetrastigmae (42.0–62.0 × 6.7–12.0 µm vs. 72.5–111.5 × 12.5–19.5 µm), and Rosellinia verticillata (GMB0082) ascospores are completely surrounded by a thin slimy sheath, but the R. tetrastigmae only has the slime at the ends (Xie et al. 2019). Moreover, stromata of R. verticillata are larger than those of R. tetrastigmae (630–735 µm high × 525–700 µm diam. vs. 300–500 mm high × 400–600 mm diam.). And R. verticillata belongs to R. emergens group (Petrini 2013) but it is different from the species which have whole spore length germ silt in this group for R. verticillata ascospores are completely surrounded by a thin slimy sheath.