Hygrophorus subsection Hygrophorus (Hygrophoraceae, Agaricales) in China Author Wang, Chao-Qun Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, Guangdong, China Author Li, Tai-Hui Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, Guangdong, China mycolab@263.net Author Zhang, Ming Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, Guangdong, China Author He, Xiao-Lan Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, Sichuan, China Author Qin, Wei-Qiang Jishou University, Zhangjiajie 427000, Hunan, China Author Liu, Tie-Zhi College of Life Sciences, Chifeng University, Chifeng 024000, Inner Mongolia, China Author Zeng, Nian-Kai College of Pharmacy-Transgenic Laboratory, Hainan Medical University, Haikou 571199, Hainan, China Author Wang, Xiang-Hua Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China Author Liu, Jian-Wei Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China Author Wei, Tie-Zheng State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China Author Xu, Jiang Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, Guangdong, China Author Li, Yue-Qiu Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, Guangdong, China Author Shen, Ya-Heng Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, Guangdong, China text MycoKeys 2020 68 49 73 http://dx.doi.org/10.3897/mycokeys.68.53264 journal article http://dx.doi.org/10.3897/mycokeys.68.53264 1314-4049-68-49 EB4D7C773441540081E96920F318F89F Hygrophorus hedrychii (Helen.) K. Kult, Ceska Mykol. 10(4): 232 (1956) Figure 8 Description. Pileus 10-50 mm broad when dried, subglobose when young, becoming hemispherical, convex to nearly plane when mature; margin incurved when young, even, expanded to sometimes slightly upturned when mature; surface covered with a thick layer of transparent and sticky materials, white, with pinkish (7A2) to yellowish (4A2) tones or cream colour (1A2) on the disc. Lamellae adnate to short decurrent, white at first, changing to pinkish-white (7A2) or pale yellow (4A3) or cream colour (1A2), waxy, with 1-3 lamellulae between two entire lamellae. Stipe 20-85 x 3-10 mm when dried, cylindrical or nearly so, often thinner at apex, usually slightly enlarged at base, uneven, with white short fibrils at apex, sometimes longitudinally lacerated when mature, covered with a layer of transparent sticky materials, white, changing to orange white (5A2, 6A2) where touched. Context thick, white when young, pale to pinkish-yellow when mature, with Cossus smell. Basidiospores (6)7-8(9) x (3.5)4-4.5(5) µm , Q = 1.5-2(2.3), Qm = 1.8, ellipsoid to subcylindrical, colourless, thin-walled, smooth. Basidia 30-40 x 6-9 µm , Q = 4.1-5.7, clavate, 4-spored; sterigmata 4-5 µm long; basal clamp connections common. Pileipellis an ixotrichoderm, composed of septate hyphae, covered with a gelatinous layer; hyphae thin-walled, 4-5 μm wide. Stipitipellis a trichoderm; hyphae 7-10 μm wide, light yellowish-brown intracellular pigment presented in a few hyphae when immersed in 5% KOH solution. Hymenophoral trama composed of septate, thin-walled and cylindrical hyaline hyphae, size 58-105 x 3-23 μm . Clamp connections present. Figure 8. Hygrophorus hedrychii . a Basidiospores b Basidia c Basidiomata (CFSZ2851) d Basidiomata (CFSZ18159) e Basidiomata (CFSZ18269) f Sold at a local market, named as "baizhenmo" . Habit, habitat and distribution. Scattered to gregarious in the north temperate forests dominated by Betula , known from north-eastern China (this study), as well as from Europe where the species was firstly discovered. Specimens examined. China, Inner Mongolia Autonomous Region, Chifeng City, Harqin Banner, Wangyedian village, 30 August 2007, T.Z. Liu (CFSZ2851); ibidem, 8 August 2017, T.Z. Liu, Y.Q. Guang & N. Liu (CFSZ18159); Hexigten Banner, Jingpeng Town, 15 August 2017, T.Z. Liu & G.L. Yu (CFSZ18269). Remarks. Macroscopically, Hygrophorus hedrychii is a distinctive waxycap, which is relatively easily recognised in the field by its white pileus disc and lamellae changing to pale ochraceous pink when mature and the host association with birch. Microscopically, the Chinese specimens agree with the descriptions by Larsson and Jacobsson (2004) for the Swedish samples and Campo (2015) for the French collections. Molecular phylogenetically, they are also identical to the European species. The Chinese samples from Inner Mongolia are traded as edible fungi at some local markets. The European H. hedrychii was not, however, treated as an edible mushroom (Larsson, personal communication). This difference may indicate different dietary habits in different areas.