Xylaria sylvatica Y.P. Wu & Q.R. Li, 2022

Wu, You-Peng, Pi, Yin-Hui, Long, Si-Han, Liu, Li-Li, Zhang, Xu, Long, Qing-De, Lin, Yan, Kang, Ying-Qian, Kang, Ji-Chuan, Wijayawardene, Nalin N. & Li, Qi-Rui, 2022, Morphology and phylogeny reveal two novel Xylaria (Xylariaceae) species from China, Phytotaxa 550 (2), pp. 130-146 : 137-141

Xylaria sylvatica Y.P. Wu & Q.R. Li , sp. nov. ( Fig. 4 )

MycoBank number: MB 842171

Type:— CHINA. Guizhou Province: Guiyang City, Guiyang Forest Park (26.2329°N, 106.451958°E), elev. 1142 m, on dead wood of unidentified plant, June 2021, Youpeng Wu, 2021GYSLGY6 (GMB0076, holotype; KUN-HKAS 122632, isotype; ex-type living culture, GMBC0076 ) .

Etymology: Refers to a forest habitat for specimen collection.

Saprobic on dead wood, forming on the host surface. Sexual morph: Stromata 0.6–1.7 cm long × 0.2–0.5 cm broad (x = 1.2 × 0.4 cm, n = 10), upright, usually solitary, unbranched, cylindrical or clavate, fertile inflated at apex, texture soft, internally white. Surface of stromata gray to black, conspicuous cracked. Stalk well defined and easy to distinguish. Perithecia 500–700 μm high × 300–700 μm broad (x = 600 × 400 μm, n = 10), oval, sphaerical to subsphaerical, embedded, closely arranged, tissue between the perithecia is white. Ostioles inconspicuous. Asci 224–313 × 10.5–20.5 μm (x = 260 × 15 μm, n = 30), 8-spored, unitunicate, cylindrical, long-stipitate, apically rounded, with a J+, wedge-shaped apical ring, blue staining in Melzer’s reagent, 9–15 μm (x = 12.2 μm, n = 30) high, 4–7 μm (mean = 5.3 μm, n = 30) wide. Ascospores 23–28.5 × 7–9.5 μm (x = 25 × 8 μm, n = 30), green grey, unicellular, ellipsoid to inequilateral, with broadly rounded ends, smooth, with a sigmoid germ slit nearly half spore-length, lacking appendages and sheaths. Asexual morph: Undetermined.

Culture characteristics: Colonies on OA reaching 3–4 mm diam. after 2 weeks at 25 °C. White at first, with regular margins, upright, velvety, with irregular outgrowths or furrows, with a peripheral fan-shaped extension spreading toward the edge; reverse blackish-brown in the center, white marginal area. After 4 weeks, Colonies on OA reaching 9 cm diam., white greyish, velvety or inflorescence, appressed with entire margins; reverse black, with brownish ring. No conidia were observed.

Notes: Phylogenetic analyses ( Fig. 1 ) indicated that X. sylvatica was closely related to X. spinulosa and X. haemorrhoidalis but formed a distinct lineage. However, X. sylvatica is distinguish from X. spinulosa by its lacking long thorns on the stromatal surface, and larger ascospores (23–28.5 × 7–9.5 μm vs. 19–23 × 6.5–8.5 μm) with a sigmoid germ slit. Xylaria sylvatica differs from X. haemorrhoidalis by its upright, solitary, unbranched, cylindrical or clavate stromata ( Li et al. 2017). Morphologically, Xylaria sylvatica shows similar traits of X. martinicensis J. Fourn. & Lechat. , and X. squamulosa F. San Martín & J.D. Rogers. , with upright, long stipitate, cylindrical or clavate stromata with fertile inflated at apex, conspicuous cracked or wrinkled on the surface of stromata. But, X. martinicensis have smaller ascospores (13–16.5 × 6–7.5 μm vs. 23–28.5 × 7–9.5 μm), with a narrow but conspicuous, straight, longitudinally oriented germ slit, which can make a distinction for X. sylvatica ( Fournier et al. 2020) . Xylaria squamulosa differs from X. sylvatica by larger ascospores (29–40 × 11–14 μm vs. 23–28.5 × 7–9.5 μm) with a straight germ slit nearly spore-length ( San Martín et al. 1989).

Figures

FIGURE 1. RAxML tree based on analysis of a combined dataset of β-tubulin, rpb2 and α-actin sequence dataset from selected species of Xylariales. Bootstrap support values for maximum likelihood (ML) greater than 50%, and Bayesian posterior probabilities (BYPP) greater than 0.90 are given at the nodes. Strain numbers are noted after the species names. Ex-type strains are in bold. Newly generated taxa are in red. The tree is rooted to the outgroup of Camillea obularia (ATCC 28093).

FIGURE 4. Xylaria sylvatica (GMB0076, holotype). A. Stromata on the surface of host. B. Stroma. C. Close-up of stromata surface, ostioles in red arrow. D. Transverse section of stroma. E. Longitudinal section of stroma. F. Culture on OA from above. G. Culture on OA from below. H–J. Asci with ascospores. K. Ascus apex with a J+, apical ring (stained in Melzer’s reagent). L, M. Ascospores with germ slits. N. Ascospores with indehiscent perispore in 10% KOH. Scale bars: B = 3 mm, C–E = 200 μm, H–N = 10 μm.