Hygrophorus fuscopapillatus C.Q. Wang & T.H. Li, 2020

Wang, Chao-Qun, Li, Tai-Hui, Zhang, Ming, He, Xiao-Lan, Qin, Wei-Qiang, Liu, Tie-Zhi, Zeng, Nian-Kai, Wang, Xiang-Hua, Liu, Jian-Wei, Wei, Tie-Zheng, Xu, Jiang, Li, Yue-Qiu & Shen, Ya-Heng, 2020, Hygrophorus subsection Hygrophorus (Hygrophoraceae, Agaricales) in China, MycoKeys 68, pp. 49-73 : 49

Hygrophorus fuscopapillatus C.Q. Wang & T.H. Li sp. nov. Figure 4

Typification.

China, Sichuan Province, Panzhihua City, Yanbian County, Gesala Ecotourism Area, elev. ca. 2900 m, 27°08'10"N, 101°11'33"E, 25 August 2013, M. Zhang & C.Q. Wang (GDGM44412, Holotype!), ITSMN378337.

Etymology.

" fusco -": dark brown, "- papillatus ": papillate. The species epithet " fuscopalillatus " (Lat.) refers to the dark brown or grey brown papilla on the pileus of the new species.

Diagnosis.

Differs from H. griseodiscus by the host association with Fagaceae , solitary habit, adnate to subdecurrent lamellae and slightly smaller basidispores measuring (6)7-9.5(10) × (4)4.5-5.5(6) µm. The ITS sequence is 95% similar to H. griseodiscus .

Description.

Pileus 20-30 mm broad, convex to hemispherical when young, applanate to plano-concave when mature, with a papilla or small umbo in the centre, white to pale grey (1B1), grey or brownish-grey to olive brown (4E2-3,4F1-3) at papilla, gradually becoming lighter from centre to margin, white to pale grey (1B1) at margin, glutinous when wet; margin even, occasionally split. Lamellae adnate to subdecurrent, white, thick, with 30-36 complete lamellae per pileus and 1-3 lamellulae between two entire lamellae. Stipe 40-60 × 4-5 mm, cylindrical, white to yellowish-grey (4B2), covered by a glutinous layer. Context thin, whitish.

Basidiospores (6)7-9.5(10) × (4)4.5-5.5(6) µm [mean length = 8.2 µm, mean width = 5 µm], Q =1.3-1.9, Qm =1.65, broadly ellipsoid, ellipsoid to oblong, smooth, hyaline. Basidia (32)35-46(48) × (6)6.5-8.5(9) µm, Q = 4.4-6.8, Qm = 5.5, clavate, thin-walled, 4-spored, with sterigmata 5-7.5 µm long. Pileipellis an ixotrichoderm, composed of septate and thin-walled cylindrical hyphae, covered with a gelatinous layer; hyphal cells 3-5 μm broad. Hymenophoral trama divergent, composed of septate, thin-walled and cylindrical hyphae; hyphal elements 13-31.5 μm broad. Clamp connections present.

Habit, habitat and distribution.

Solitary, on the ground of Fagaceae -dominated forests, so far only known from Sichuan and Yunnan provinces in Southwest China.

Additional specimens examined.

China, Yunnan Province, Yulong County, Jade Dragon Snow Mountain, Lijiang Alpine Botanic Garden, on the ground of Quercus pannosa dominated forest, elev. ca. 3267 m, 27°00'02"N, 100°10'52"E, 31 August 2019, J.W. Liu (LJW1858); Binchuan County, Jizushan, on the ground of Castanopsis and Lithocarpus dominated forest, elev. ca. 2853 m, 25°58'06"N, 100°21'39"E, 18 September 2019, X.H. Wang (XHW6609).

Remarks.

Hygrophorus fuscopapillatus is distinguished by the solitary basidiomes, the brownish-grey to olive brown papilla in the pileus centre, the broadly ellipsoid, ellipsoid to oblong basidiospores measuring (6)7-9.5(10) × (4)4.5-5.5(6) µm.

Amongst the members of subsect. Hygrophours , H. griseodiscus closely resembles H. fuscopapillatus ; however, H. griseodiscus differs from H. fuscopapillatus by the host association with Pinaceae , the larger pileus (2-4.5 cm broad), the emarginate lamellae with decurrent tooth, the larger basidispores measuring (7)8-10(10.5) × (4)4.5-6(6.5) µm and the broader basidia (7-11 mm broad). In addition, H. brunneodiscus is distinguished from H. fuscopapillatus by the broader pileus (2-5 cm in diam.) and the brownish pileus disc. Hygrophorus cossus is separated by the larger pileus (3-9 cm in diam.), greyish-white lamellae with a cream yellow tint and a thicker stipe (0.6-2 cm broad) ( Larsson and Jacobsson 2004). Hygrophorus discoxanthus differs by the rusty brown lamellae when mature and the wider stipe (up to 1.2 cm broad); H. eburneus is distinguished by the gregarious habit, the more robust basidiomes and the white pileus ( Candusso 1997, Larsson and Jacobsson 2004). Hygrophorus glutiniceps differs by the subtropical to tropical distribution and smaller basidiospores measuring (5)6-8.5(10) × (3.5)4-6 µm. Hygrophorus hedrychii is separated by the larger basidiomes (pileus up to 8 cm in diam.) and the reddish-yellow pileus centre ( Larsson and Jacobsson 2004). Hygrophorus scabrellus is distinguished by the off-white with dark green pileus, the off-white to beige lamellae and the much smaller basidiospores measuring 6.5 × 3.84 µm ( Naseer et al. 2019).

Figures

Figure 4. Hygrophorus fuscopapillatus. a, b Basidiomata (GDGM 44412, Holotype) c, d Basidiospores Basidiomata (LJW 1858) e, f Basidiospores and Basidia (XHW 6609) g, h Basidiospores and Basidia (GDGM 44412) i, j Basidiospores and Basidia (LJW 1858). Scale bars: 2 cm (a-f).