Boletus littoreus (Boletaceae, Boletales), a new species with a white basidioma from Hainan, China Author Yang, Yu-Ying 0000-0003-4674-4032 Key Laboratory of Tropical Translational Medicine of Ministry of Education, Transgenic Laboratory, Hainan Medical University, Haikou 571199, China & 2060647083 @ qq. com; https: // orcid. org / 0000 - 0003 - 4674 - 4032 2060647083@qq.com Author Xu, Chang 0000-0003-0418-5463 Key Laboratory of Tropical Translational Medicine of Ministry of Education, Transgenic Laboratory, Hainan Medical University, Haikou 571199, China & 751116803 @ qq. com; https: // orcid. org / 0000 - 0003 - 0418 - 5463 751116803@qq.com Author Wang, Yi 0000-0001-7607-5680 Key Laboratory of Tropical Translational Medicine of Ministry of Education, Transgenic Laboratory, Hainan Medical University, Haikou 571199, China & 996305245 @ qq. com; https: // orcid. org / 0000 - 0001 - 7607 - 5680 996305245@qq.com Author Li, Le 0000-0002-2055-2158 Haikou Duotan Wetlands Institute, Haikou 570125, China & 331800974 @ qq. com; https: // orcid. org / 0000 - 0002 - 2055 - 2158 331800974@qq.com Author Yuan, Lang-Xing 0000-0003-2102-9075 Haikou Duotan Wetlands Institute, Haikou 570125, China & yuanlangxing @ 163. com; https: // orcid. org / 0000 - 0003 - 2102 - 9075 Author Zhao, Fu-Wei 0000-0003-1523-6668 Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of China, Nanjing, 210042, China & zhaofuwei @ outlook. com; https: // orcid. org / 0000 - 0003 - 1523 - 6668 zhaofuwei@outlook.com Author Zeng, Nian- Kai 0000-0001-7651-4524 Key Laboratory of Tropical Translational Medicine of Ministry of Education, Transgenic Laboratory, Hainan Medical University, Haikou 571199, China & niankaiz @ 163. com; https: // orcid. org / 0000 - 0001 - 7651 - 4524 text Phytotaxa 2022 2022-07-12 554 2 176 188 http://dx.doi.org/10.11646/phytotaxa.554.2.6 journal article 94522 10.11646/phytotaxa.554.2.6 92a6ea2c-cbfc-4ad3-9892-9fd896b6ca61 1179-3163 6820978 Boletus littoreus N.K. Zeng, Y. Wang, C. Xu & Y.Y. Yang sp. nov. ( Figs. 3–4 ) MycoBank: MB842533 Etymology:—Latin “ littoreus ” refers to the new species growing near the seaside. Diagnosis:—Differs from closest species of Boletus s. str. , viz ., B. austroedulis Halling & Fechner (2014: 832) by a stipe without reticulations, a pileipellis composed of elliptic-fusiform to subglobose, sometimes filamentous. hyphae in chains, and an association with trees of Dipterocarpaceae . Holotype :— CHINA . Hainan Province : Wanning City , Shimei Bay , elev. 5 m , 28 August 2020 , L . X. Yuan 3 ( FHMU5919 ). GenBank accession numbers: 28 S = OM 234787 , ITS = OM 234789 , TEF1 = ON 505823 , RPB2 = ON 494596 . Description:— Basidiomata small to medium-sized. Pileus 4.7–6 cm in diam, subhemispherical at first, then convex to applanate; margin decurved, sometimes slightly uplifted; surface dry, nearly smooth, white (1A1), sometimes staining brown (3C5) when handled; context 0.2–5 mm thick in the center of pileus, white (1A1), unchanging in color when injured. Hymenophore poroid, adnate to slightly depressed around apex of stipe, stuffed with white (1B1) mycelium when young; pores angular, yellow when young, then brownish yellow (1A2), unchanging in color when injured; tubes approximately 4–5 mm in length, yellowish, unchanging in color when injured. Stipe 8.2–9.2 × 0.15–0.7 cm , central, subcylindrical, solid; surface dry, white (1A1) tinged brownish (3C5), without reticulations; context white (1A1), unchanging in color when injured. Basal mycelium whitish (1A1). Odor not distinctive. FIGURE 3. Basidiomata of Boletus littoreus . ( a , c from FHMU5923; b , d from FHMU5919, holotype). a–c photos by N.K. Zeng; d photo by L.X. Yuan. Basidiospores [60/3/2] (9–)9.5–11(–11.5) × (4–)4.5–5(–5.5) μm, Q =(1.9–)2–2.40 (–2.5), Qm =2.16 ± 0.142, broadly ellipsoid to cylindrical, slightly thick-walled (<1 μm), olive brown to yellowish brown in KOH, smooth. Basidia 20–25 × 8–11μm, clavate, 4-spored, thin-walled, colorless in KOH; sterigmata 3–5 μm in length. Cheilocystidia 27–72 × 9–13 μm, abundant, subfusiform or fusoid-ventricose, thin-walled, colorless in KOH. Pleurocystidia 40–74 × 7–14 μm, subfusiform or fusoid-ventricose, thin-walled, colorless in KOH. Hymenophoral trama boletoid, made up of hyphae 3–14 μm in diam, thin- to slightly thick-walled (up to 1 μm), colorless in KOH. Pileipellis a trichoderm 100–200 μm in thickness, composed of thin-walled, occasionally branching, colorless to yellowish in KOH, ellipticfusiform to subglobose, sometimes filamentous, hyphae (3–20 μm in diam) in chains; terminal cells 16–75 × 4–12 μm, subclavate, subcylindrical or subfusiform. Pileal trama made up of hyphae 4–15 μm in diam, thin- to slightly thick-walled (<1 μm), colorless to yellowish in KOH. Stipitipellis a hymeniform composed of colorless to yellowish in KOH, thin- to slightly thick-walled (<1 μm) erect hyphae, with clavate, subclavate or subfusiform terminal cells (13–37 × 5–13 μm). Stipe trama made up of longitudinally arranged, parallel hyphae 4–16 μm in diam, cylindrical, thin- to slightly thick-walled (up to 1 μm), colorless in KOH. Clamp connections absent in all tissues. Habit and habitat:—Scattered on the floor of a forest dominated by Vatica mangachapoi . Known distribution:—Southern China ( Hainan Province ). Additional materials examined:— CHINA . Hainan Province : Wanning City , Shimei Bay , elev. 5 m , 28 August 2020 , N . K . Zeng 4861 ( FHMU5923 ) .