Crocinoboletus, a new genus of Boletaceae (Boletales) with unusual boletocrocin polyene pigments Author Zeng, Nian-Kai Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China & Hainan Provincial Key Laboratory of R & D on Tropical Medicinal Plants, College of Pharmacy, Hainan Medical University, Haikou 571199, China Author Wu, Gang Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China Author Li, Yan-Chun Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China Author Liang, Zhi-Qun College of Materials and Chemistry Engineering, Hainan University, Haikou 570228, China Author Yang, Zhu L. Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China text Phytotaxa 2014 2014-08-08 175 3 133 140 http://dx.doi.org/10.11646/phytotaxa.175.3.2 journal article 10.11646/phytotaxa.175.3.2 1179-3163 5143841 Crocinoboletus laetissimus (Hongo) N.K. Zeng, Zhu L. Yang & G. Wu , comb. nov. Figs. 1 , 3 MycoBank: MB 809230 Boletus laetissimus Hongo, Memoirs of the Faculty of Liberal Arts and Education, Shiga University 18: 49, Fig. 20/1–3, 1968 Pileus 3.8–7 cm in diameter, subhemispherical when young, then convex to applanate; surface dry, golden yellow, bright orange to reddish orange, covered with minute, dark reddish brown squamules, turning bluish olivaceous quickly, then blackening when bruised; margin decurved; context vivid golden yellow, turning bluish olivaceous quickly when bruised. Hymenophore poroid, adnate or slightly depressed around apex of stipe; pores subcircular, minute, about 0.7 mm in diameter, orange, turning bluish olivaceous quickly, then blackening when bruised; tubes 3–4 mm in depth, golden yellow to orange, turning bluish olivaceous quickly, then blackening when bruised. Stipe 6–11 × 1.2–2 cm , centrally attached, subcylindric, solid; surface dry, concolorous with the pileus, sometimes covered with dark reddish orange squamules, turning bluish olivaceous quickly, then blackening when bruised; context vivid golden yellow, turning bluish olivaceous quickly when bruised; annulus absent. Basal mycelium orangish yellow. Odor not distinct. Taste not distinct. Basidia 24–35 × 7–10 μm, clavate, thin-walled, 4-spored; colorless to yellowish in KOH; sterigmata 5–6 μm in length. Basidiospores [56/2/2](9–)9.2–12(–14) × 4–5 μm, Q = (1.84–)1.98–2.60 (–3.00), Q m = 2.23 ± 0.22, subfusiform to ellipsoid, slightly thick-walled (up to 0.5 μm), olive brown to yellowish brown in KOH, smooth, inamyloid. Hymenophoral trama subboletoid with weakly gelatinous lateral strata. Cheilocystidia 19–28 × 3.5–5 μm, subfusiform or fusiform, thin-walled, colorless, brownish yellow to yellowish brown in KOH, no encrustations. Pleurocystidia 28–44 × 4–8 μm, fusiform or subfusiform, thin-walled, colorless, brownish yellow to yellowish brown in KOH, no encrustations. Pileipellis an interwoven trichoderm at the middle part of the pileus and a cutis at the margin of the pileus; composed of thin-walled hyphae 3–6 μm wide, occasionally branched, with terminal cells 18–80 × 2.5–4 μm, narrowly clavate or subcylindrical, with obtuse apex; yellowish to yellowish brown in KOH. Pileal trama made up of hyphae 3–6 μm in diameter, thin-walled, colorless to yellowish in KOH. Stipitipellis a trichoderm-like structure composed of thin- to slightly thick-walled (up to 0.5 μm) hyphae 3–12.5 wide, with narrowly or broadly clavate, subfusiform terminal cells measuring 13–30 × (3–)5–12.5 μm, yellowish to yellowish brown in KOH, and occasionally with clavate, 4-spored basidia at the apex of the stipe. Stipe trama composed of cylindrical parallel hyphae 4–12 μm wide, thin- to slightly thick-walled (up to 1 μm), colorless to yellowish in KOH. Clamp connections absent in all tissues. Habitat and habitat : Solitary on the ground in mixed forests of Fagaceae and Pinaceae . Known distribution : Japan ( Hongo 1968 , 1984 ), subtropical and tropical regions of China . Materials examined : CHINA . Yunnan Province : Dai Autonomous Prefecture of Xishuangbanna , 9 July 2006 , Y . C . Li 478 ( HKAS 50232 ); Nanhua County , bought from agriculture supermarket, 2 August 2009 , Y . C . Li 1953 ( HKAS 59701 ) .