Xylaria polysporicola Hai X. Ma & X.Y. Pan, 2022

Pan, Xiao-Yan, Song, Zi-Kun, Qu, Zhi, Liu, Tie-Dong & Ma, Hai-Xia, 2022, Three new Xylaria species (Xylariaceae, Xylariales) on fallen leaves from Hainan Tropical Rainforest National Park, MycoKeys 86, pp. 47-63 : 47

Xylaria polysporicola Hai X. Ma & X.Y. Pan sp. nov.

Figure 4

Diagnosis.

Differs from X. phyllocharis by its half-exposed to fully exposed perithecial contours, the fertile part cylindrical and larger perithecia. Differs from X. phyllophila by its smaller ascospores. Differs from X. amphithele by its cylindrical stromata.

Typification.

China. Hainan Province, Lingshui County, Diaoluoshan Natural Reserve, on fallen leaves of Polyspora hainanensis ( Theaceae ), 31 December 2020, Haixia Ma (holotype, FCATAS 848).

Etymology.

" Xylaria polysporicola " refers to the growth on leaves of Polyspora hainanensis .

Teleomorph.

Stromata solitary, upright or prostrate, cylindrical, unbranched or occasionally branched, 1-4 cm total length, with acute sterile apex up to 2 mm long; fertile part 2-15 mm long × 0.5-1.6 mm diam., usually consists of closely packed perithecia and occasionally with scattered perithecia; the stipe 5-30 mm long × 0.3-1 mm diam., glabrous, finely longitudinally striate, the base slightly swollen; surface roughened, with half-exposed to fully exposed perithecial contours and wrinkles. Externally black, interior white. Texture soft. Perithecia subglobose, 0.4-0.6 mm diam. Ostioles papillate. Asci with eight ascospores arranged in uniseriate manner, cylindrical, 115-185 µm total length, the spore-bearing parts 75-100 µm long × 6.5-9 µm broad, the stipes 30-90 µm long, with apical apparatus bluing in Melzer’s reagent, inverted hat-shaped or urn-shaped, 2.5-4.5 µm high × 2-3.2 µm broad. Ascospores brown to dark-brown, unicellular, ellipsoidal-inequilateral, with broadly rounded ends, one end slightly pinched sometimes, smooth, (11.5-)12.5-14.5(-15) × 5.5-8 µm (M = 13.2 × 6.4 µm, n=60), with straight germ slit slightly less than spore-length, a slimy sheath or non-cellular appendages visible occasionally in Indian ink.

Additional specimens examined.

China. Hainan Province, Lingshui County, Diaoluoshan Natural Reserve , on fallen leaves of Polyspora hainanensis , 31 December 2020, Haixia Ma (FCATAS 849); 5 July 2019, Haixia Ma (FCATAS 850 & 851) .

Remarks.

Xylaria polysporicola is morphologically similar to X. phyllocharis Mont. However, X. phyllocharis has fully immersed perithecia, the fertile part with peg-like structures and smaller perithecia 0.2-0.3 mm diam ( San Martín and Rogers 1989; Fournier et al. 2020). Xylaria polysporicola is similar to Xylaria sp. (80082005) from Taiwan in stromatal morphology, but the latter has slightly smaller stroma (11-14 mm total length × 1 mm diam. vs. 10-40 mm total length × 0.5-1.6 mm diam.), hard texture, slightly larger ascospores 13.5-16.5 × 5-6 µm, with narrowly rounded ends ( Ju and Rogers 1999). Xylaria phyllophila Ces. somewhat resembles X. polysporicola in stromatal morphology, but the former has larger ascospores 20 × 10 µm ( Cooke 1883).

Xylaria polysporicola is somewhat similar to X. amphithele F. San Martín & J.D. Rogers in shape and size of apical apparatus and ascospores. However, X. amphithele has globose to conical stromata with 3-4 to 20 naked perithecia ( San Martín and Rogers 1989). In the phylogenetic tree, X. polysporicola formed a lineage close to X. amphithele and X. ficicola , but is distant from X. phyllocharis .

Figures

Figure 4. Xylaria polysporicola (FCATAS 848, holotype) a, b stromata on leaves (b, FCATAS 851) c stromatal surface d section through stroma, showing perithecia e, g asci and ascal apical ring in Melzer's reagent f, i ascal apical ring in Melzer's reagent h asci in black India ink j ascospore with germ slit in 1 % SDS k, l ascospore in water m, n ascospore showing a slimy sheath and non-cellular appendages in India ink (FCATAS 850) o Ascospore in 1 % SDS. Scale bars: 1 cm (a, b); 0.2 mm (c, d); 10 µm (e-o).