Xylaria orientalis W. Y. Zeng & Q. R. Li, 2024

Zeng, Wenyu, Habib, Kamran, Zhou, Xin, Ren, Yulin, Shen, Xiangchun, Wang, Bei, Kang, Yingqian, Kang, Jichuan & Li, Qirui, 2024, Morphology and multigene phylogeny reveal four new Xylaria (Xylariales, Xylariaceae) species from karst region in China, MycoKeys 108, pp. 169-196 : 169-196

Xylaria orientalis W. Y. Zeng & Q. R. Li sp. nov.

Fig. 4

Etymology.

The specific epithet refers to the name of host, Hedyosmum orientalis Merr. & Chun.

Type.

China. • Guangxi Province, Rongshui County, Jiuwanshan National Na-ture Reserve , 25 ° 10 ' 42 ″ N, 108 ° 44 ' 58 ″ E, elev. 984 m, on fallen leaves of Hedyosmum orientalis ( Chloranthaceae ), August 2023, Wenyu Zeng & Xin Zhou, JWS 2 ( GMB 4701 Holotype; KUN-HKAS 134917 Isotype; GMBC 4701 ex-type) .

Description.

Saprobic on fallen leaves of Hedyosmum orientalis . Sexual morph: Stromata 1.7–8.5 cm long, upright, solitary, black, thread-like, unbranched, with a long sterile filiform apex up to 0.2–4 cm long, fertile part 4–13 mm long × 0.5–1 mm wide, glabrous, finely longitudinally striate, the base slightly swollen, with 2 / 3 - exposed to fully exposed perithecial mounds. The exterior is black, interior white, has soft texture. Perithecia subglobose, 350–573 μm diam. Ostioles papillate. Asci 81–115 × 4.6–6.6 μm (x ̄ = 98 × 5.6 μm, n = 30), 8 - spored, unitunicate, cylindrical, with a J +, tubular to wedge-shaped apical apparatus bluing in Melzer’s reagent, 2.1–4.1 × 2.8–4.0 μm (x ̄ = 3.1 × 3.4 μm, n = 30). Ascospores 9.4–11.2 × 3.5–5.0 μm (x ̄ = 10.2 × 4.3 μm, n = 30), uniseriate, unicellular, dark brown to black, ellipsoid-inequilateral, with narrowly rounded ends, smooth, straight germ slit of a spore-length, lacking sheath, epispore smooth. Asexual morph: Undetermined.

Culture characteristics.

Colonies on OA reaching 12–15 mm diam. after 2 weeks at 25 ° C, white at first, with irregular margins, then extension spreading toward the edge of the Petri dish; the overall color is light white.

Additional material examined.

China. • Guangxi Province, Rongshui County, Jiuwanshan National Nature Reserve , 25 ° 10 ' 42 ″ N, 108 ° 44 ' 58 ″ E, elev. 765 m, on fallen leaves of Hedyosmum orientalis , August 2023, Wenyu Zeng & Xin Zhou, JWS 2-1 ( GMB 4705 ; GMBC 4705 ) .

Notes.

Morphologically and phylogenetically (Fig. 1 ), Xylaria orientalis is closely related to X. filiformis and X. crinalis , sharing similar stromatal characteristics ( Hashemi et al. 2014; Ma and Yu 2018). However, differences are observed in their asci and ascospores. The ascospores of X. orientalis are distinctly dark brown to black, whereas those of X. filiformis are light brown. Additionally, X. filiformis has larger asci 130–155 × 5.5–6.2 μm, and ascospores 12.5–21 × 4.5–5.5 μm ( Hashemi et al. 2014). Xylaria crinalis differs by having a few scattered perithecia on the stroma, a more or less conspicuous germ slit, a narrower apical apparatus 1.5–2.5 µm broad, larger ascospores 14–17.5 × 3.5–6 µm, and its occurrence on wood. Morphologically, Xylaria orientalis also shares stromatal characteristics with X. vagans Petch. However , X. vagans is distinguished by its black rhizomorphoid mycelium connecting dead leaves, asci lacking a J + apical apparatus, and ascospores with broadly rounded ends that lack a germ slit ( Ju and Hsieh 2023).

Figures

Figure 1. RAxML tree based on a combined ITS, TUB 2 and rpb 2 gene sequences data set. Bootstrap support values for maximum likelihood (ML) > 75 % and Bayesian posterior probabilities (BPP) > 0.95 are displayed above or below the respective branches (ML / BI). The newly described species are marked and red. Type materials were marked bold.

Figure 4. Xylaria orientalis (GMB 4701) A type material B stroma C surface of stroma D transverse section of stroma E longitudinal section of stroma F-H asci with ascospores I a J +, ascus apical apparatus (stained in Melzer’s Reagent) J – L ascospores M colonies of Xylaria orientalis on OA. Scale bars: 0.5 mm (C – E); 15 µm (F – L).