Gyroporus brunneofloccosus T.H. Li, W.Q. Deng & B. Song, Fungal Diversity 12: 123 (2013), figs 1-3

Huang, Cong, Zhang, Ming, Wu, Xing-Liang, Wu, Gang, Xu, Jian-Ping, Yang, Zhu L. & Li, Yan-Chun, 2021, Cyanescent Gyroporus (Gyroporaceae, Boletales) from China, MycoKeys 81, pp. 165-183 : 165

Gyroporus brunneofloccosus T.H. Li, W.Q. Deng & B. Song, Fungal Diversity 12: 123 (2013), figs 1-3

Figs 3e-h , 5

Description.

Pileus 6-9 cm in diam., hemispherical to sub-hemispherical when young, applanate to plano-convex when mature, dark brown (7E5-6) to brown (6E7-8) when young and brown to light red-brown (8E5-6) when mature; surface covered with concolorous floccose-scaly to coarsely tomentose squamules, always cracked with olivaceous yellow (2D5-6) background exposed when mature or aged, margin always extended; context white (1A1), staining cerulean blue (23C6-7) or greenish-blue (24B6-7) to dark blue (23F7-8) or deep blue (22E6-8) when bruised. Hymenophore adnate to obviously depressed around apex of stipe; surface yellowish (29B3) to pale yellow (30B3) when young and then greenish-yellow (29B5-6) when mature or aged, staining cerulean blue to greenish-blue when bruised; pores angular to roundish, 1-2 per mm; tubes 3-9 mm long, concolorous with hymenophoral surface, staining cerulean blue to greenish-blue when bruised. Stipe 4.5-6 × 1-2 cm, subcylindrical to clavate, concolorous with pileal surface when mature, but much paler when young; surface covered with tomentose to fibrillose squamules; context white to cream, spongy then hollow when mature, staining cerulean blue to greenish-blue or dark blue to deep blue when bruised. Odour and taste indistinct.

Basidia 22-32 × 8-11 µm, clavate, 4-spored, hyaline in KOH, yellowish in Melzer’s Reagent. Basidiospores [60/3/2] (8) 8.5-10 × 5-6 µm, (Q = 1.42 - 1.90, Qm = 1.62 ± 0.11) ellipsoid, smooth, hyaline to yellowish in KOH and primrose yellow to yellowish-brown in Melzer’s Reagent. Cheilocystidia 27-44 × 9-12 μm, clavate to subfusiform, thin-walled, hyaline in KOH and yellowish in Melzer’s Reagent. Pleurocystidia not observed. Tube trama composed of 8-10 μm wide interwoven hyphae, hyaline in KOH, yellowish in Melzer’s Reagent. Squamules on pileus composed of 7-10 μm wide interwoven hyphae, hyaline to yellowish in KOH, yellowish to brownish-yellow in Melzer’s Reagent; terminal cells 80-180 × 8-10 μm, clavate to subcylindrical. Clamp connections frequently present in all tissues.

Specimens examined.

China. Yunnan Province: Wenshan County, Malipo Village , alt. 1200 m, 14 Oct 2017, Wu 2644 (KUN-HKAS 107735, GenBank accession numbers: MW149436 for ITS, MW151267 for nrLSU, MW452611 for atp6) . Guangdong Province: Zhaoqing County, Dinghu Shan Nature Reserve, alt. 200 m, 28 Aug 2018, J.Y. Xu (GDGM 74638, GenBank accession numbers: MW149437 for ITS, MW151266 for nrLSU); Shenzhen, Songzikeng Forest Park, alt. 70 m, 19 Jul 2019, J.Y. Xu (GDGM 77125) .

Habitat and distribution.

Scattered on soil in tropical forests dominated by Castanopsis ( Fagaceae ), Quercus ( Fagaceae ) and Pinus ( Pinaceae ). Currently known from southern and south-western China.

Discussion.

Gyroporus brunneofloccosus , originally described from southern China, is characterised by the initially dark brown to brown and then brown to light red-brown pileus with concolorous floccose-scaly to coarsely tomentose squamules, the extended pileal margin, the white pileal context staining cerulean blue or greenish-blue to dark blue or deep blue when bruised, the initially yellowish to pale yellow and then greenish-yellow hymenophore staining cerulean blue to greenish-blue when bruised, the brownish to brown or light red-brown stipe, the spongy and then hollow context in the stipe, the frequent clamp connections in all tissues, the ellipsoid basidiospores and the distribution in tropical forests dominated by plants of the families Fagaceae and Pinaceae ( Li et al. 2003).

In China, G. brunneofloccosus was misidentified as G. cyanescens by Bi et al. (1990, 1994), Ying and Zang (1994) and Mao (2000). However, these two species can be separated both by phylogenetic and morphological evidence. Our phylogenetic analysis of atp6 data (Fig. 1 ) indicates that G. brunneofloccosus is closely related to G. phaeocyanescens . However, G. phaeocyanescens , originally described from Belize by Singer et al. (1983), has fulvous to snuff brown pileus and relatively large basidiospores measuring 9.3-14.7 × 5.3-6.7 µm ( Singer et al. 1983; Li et al. 2003).

Figures

Figure 1. Maximum Likelihood phylogenetic tree of Gyroporus inferred from the atp 6 dataset. Bootstrap frequencies (> 50 %) are shown above or below supported branches. Newly-sequenced collections are indicated in bold. Species vouchers and countries of origin are provided after the species name successively.

Figure 3. a-c Gyroporus alpinus (KUN-HKAS 56318, type, photos by Y. C. Li) d Gyroporus flavocyanescens (KUN-HKAS 76966, type, photo by X. L. Wu) e-h G. brunneofloccosus (e KUN-HKAS 107735, photo by G. Wu f GDGM 77125, photo by J. Y. Xu g, h GDGM 74638, photos by J. Y. Xu). Scale bars: 2 cm.

Figure 5. Microscopic features of G. brunneofloccosus (HKAS 107735) a basidia b cheilocystidia c basidiospores d pileipellis (squamules).