Fungal Biodiversity Profiles 81 - 90 Author Wang, Xiang-Hua CAS Key Laboratory for Plant Diversity and Biogeography of East Asia,) xhwang @ mail. kib. ac. cn xhwang@mail.kib.ac Author Das, Kanad Author Bera, Ishika Cryptogamic Unit, Botanical Survey of India, P. O. Botanic Garden, Howrah 711103 (India) daskanadbsi @ gmail. com iamishika 6 @ gmail. com daskanadbsi@gmail.com Author Chen, Yu-Hui College of Life Sciences, Southwest Forestry University, Kunming 650224 (China) Author Bhatt, Rajendra Prasad Author Ghosh, Aniket Department of Botany & Microbiology, H. N. B. Garhwal University (A Central University), Srinagar, Garhwal, 246174, Uttarakhand (India) bhatt. rajendra 123 @ gmail. com ghosh. aniket 87 @ gmail. com Author Hembrom, Manoj Emanuel Central National Herbarium, Botanical Survey of India, P. O. Botanic Garden, Howrah 711103 (India) manojhembrom @ yahoo. co. in manojhembrom@yahoo.co.in Author Hofstetter, Valérie Department of Plant Protection, Agroscope Changins-Wädenswil - ACW, Rte De Duiller, CH- 1260 Nyon 1 (Switzerland) valerie. hofstetter @ agroscope. admin. ch hofstetter@agroscope.admin.ch Author Parihar, Arvind Cryptogamic Unit, Botanical Survey of India, P. O. Botanic Garden, Howrah 711103 (India) arvind _ peace @ rediffmail. com peace@rediffmail.com Author Vizzini, Alfredo Department of Life Sciences and Systems Biology, University of Torino, Viale P. A. Mattioli 25, I- 10125 Torino (Italy) alfredo. vizzini @ unito. it vizzini@unito.it Author Xu, Tai-Min College of Life Sciences, Southwest Forestry University, Kunming 650224 (China) Author Zhao, Chang-Lin College of Biodiversity Conservation and Utilisation, Southwest Forestry University, Kunming 650224 (China) fungichanglinz @ 163. com text Cryptogamie, Mycologie 2019 2019-08-27 20 5 57 95 https://bioone.org/journals/cryptogamie-mycologie/volume-40/issue-5/cryptogamie-mycologie2019v40a5/Fungal-Biodiversity-Profiles-81-90/10.5252/cryptogamie-mycologie2019v40a5.full journal article 246330 10.5252/cryptogamie-mycologie2019v40a5 01060200-4830-4385-85aa-2b5fa809184d 1776-100X 7814899 85. Lactarius exilis X.H. Wang , sp. nov. ( Figs 9 ; 10B ; 13 ) A small slender species with pileus with a conical center, white latex, globose reticulate spores, absence of pleuromacrocystidia, numerous cheilomacrocystidia and pileipellis a (hymeno)epithelium. A long INDEL in the ITS1 region is also characteristic. TYPUS. — China . Shanxi Prov. , Xia Co. , Sijiao , Tanghui , under Quercus trees, 15.VIII.2015 , coll. X.H. Wang , no. 3683 ( holo- , KUN [ HKAS 89954 ]!). MYCOBANK. — MB 829288. GENBANK. — MK351982 - MK351984 (ITS). ETYMOLOGY. — Referring to the slender fruiting bodies. ADDITIONAL SPECIMENS EXAMINED. — China . Henan Prov. , Xinyang, Jigong Mt., between Laoyingwo and Xiannütan, 295 m a.s.l., 25.VIII.2015 , coll. X.H. Wang, no. 3783 (KUN[HKAS 90043]). South Korea . Seoul , Donggureung Nine Royal Tombs, under Quercus trees, 15.VIII.2011 , coll. X.H. Wang, no. 2966 ( KUN [ HKAS 73523]). HABIT, HABITAT AND DISTRIBUTION. — Caespitose or 1-4 individuals growing together, in fagaceous forests. Northern ( Shanxi Prov. ) and central ( Henan Prov. ) China and South Korea . DESCRIPTION Basidiomata Small, slender. Pileus 6-15 mm in diam., at first convex with a pointed papilla, becoming plano-convex with a depressed center when mature, ± sulcate, margin sometimes crenate; surface dry, somewhat areolate-rimose, dark brown or dark reddish brown when young, later remaining so or becoming yellowish brown, orange brown, hygrophanous, radially rugose. FIG. 13. — Lactarius exilis X.H. Wang , sp. nov. (HKAS 89954, holotype): A , basidiospores; B , cheilomacrocystidia; C , lamella edge ; D , pileipellis. Scale bars: A, 5 μm; B, 20 μm; C, D, 25 μm. Context Very thin (< 0.5 mm ), concolorous with the lamellae. Lamellae 1-3mm broad, decurrent, subdistant, pale yellow,grayish orange. Stipe 20-40 × 1-2 mm , cylindrical, equal or gradually enlarged downward; surface dry, smooth, with silky luster, nearly concolorous with the lamellae or light brown. Latex White, watery, neither discoloring nor staining. Odor None. Spore print Not obtained. Basidiospores (80/4/3) 7.0-7.7-8.5 (9.0) × 6.5-7.2-8.0 (8.5) Μm [Q = 1.00- 1.12 (1.14), Q = 1.06 ± 0.03] [ holotype (40/2/1) 7.0-7.7-8.5 (9.0) × 6.5-7.3-8.0 (8.5) Μm, Q = 1.00-1.10 (1.14), Q = 1.06 ± 0.03], globose, subglobose; ornamentation 0.8-1.5 (2.0) Μm high, of ridges connected, forming an incomplete to complete reticulum, often with subtransparent (less amyloid) dots in the ridges or at the crossing points of ridges; plage not amyloid or slightly distally amyloid. Basidia 4-spored, 35-52 × 8-13 Μm, clavate. Pleuromacrocystidia Absent. Pseudocystidia Uncommon to common, 2-4 Μm broad, often slightly enlarged at the apex, some forking. Lamella edge Sterile, rarely with scattered basidia; cheilomacrocystidia numerous, 25-60 × 4-7 Μm, subfusiform, cylindrical, apex mostly mucronate or moniliform, with sparse to agglomerated contents. Pileipellis An epithelium, 50-100 Μm thick; cells 15-30 Μm in diam., globose, ellipsoid, terminal cells often ellipsoid, colorless, hyphae beneath globose cells 5-10 Μm broad, colorless. Stipitipellis A cutis, 40-50 Μm thick, closely packed; hyphae 3-5 Μm broad, pale yellowish brown. Pileus and stipe trama With numerous rosettes. FIG. 14. — Lactarius flaviaquosus X.H. Wang , sp. nov. (HKAS 104207, holotype): A , basidiospores; B , pleuromacrocystidia; C , lamella edge ; D , pileipellis. Scale bars: A, 5 μm; B, 20 μm; C, D, 25 μm. NOTES The combination of pileipellis an epithelium, absence of pleuromacrocystidia and abundant cheilomacrocystidia of L. exilis X.H. Wang , sp. nov. , is shared by L. castanopsidis and L. resinosus X.H. Wang , sp. nov. (described below). Those two species have spores with deeply winged zebroid ornamentations and brownish hyphae underlying the pileipellis. Lactarius exilis X.H. Wang , sp. nov. , is similar to European L. obscuratus , L. cyathuliformis and L. omphaliformis and Thai L. crenulatulus Wisitrassameewong & Verbeken in the slender habit and the pileipellis an epithelium. The three European species have pleuromacrocystidia and ellipsoid spores (Heilmann-Clausen et al. 1998; Basso 1999 ). The Thai species lacks cheilomacrocystidia and has a more crenulate pileus and white pruinose stipe base ( Wisitrassameewong et al. 2014 ). Japanese L. cyathula f. japonicus Hongo looks similar. It has bigger ellipsoid spores and lacks macrocystidia ( Hongo 1971 ) . The long INDEL in the ITS1 region in L. castanopsidis , L. exilis X.H. Wang , sp. nov. , and L. resinosus X.H. Wang , sp. nov. , is unique among the members of L. subg. Russularia . This long INDEL is also present in several species of L. subg. Lactarius with violeting latex [e.g. L. cascadensis Hesler & A.H. Sm. and L. luridus (Pers.) Gray ]. Using the whole ITS or ITS1 region to BLAST gave hits to these not closely related species.