Morphological characteristics and phylogenetic analyses revealed two additional taxa in Cyathus (Agaricales, Basidiomycota) Author Duan, Zi-Yan 0000-0003-2673-8890 Key Laboratory of Forest Disaster Warning and Control in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, P. R. China & fungiziyand @ 163. com; https: // orcid. org / 0000 - 0003 - 2673 - 8890 Author Yang, Xin 0009-0009-7755-0581 Key Laboratory of Forest Disaster Warning and Control in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, P. R. China & Fungixiny @ 163. com; https: // orcid. org / 0009 - 0009 - 7755 - 0581 Author Liu, Chao-Mao 0000-0002-9548-9683 Key Laboratory of Forest Disaster Warning and Control in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, P. R. China & lcm 1987 swkx @ 163. com; https: // orcid. org / 0000 - 0002 - 9548 - 9683 Author Zhao, Chang-Lin 0000-0002-8668-1075 Key Laboratory of Forest Disaster Warning and Control in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, P. R. China & Yunnan Key Laboratory of Gastrodia and Fungal Symbiotic Biology, Zhaotong University, 657000, P. R. China & Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, P. R. China & fungichanglinz @ 163. com; https: // orcid. org / 0000 - 0002 - 8668 - 1075 text Phytotaxa 2023 2023-05-19 598 1 1 20 http://dx.doi.org/10.11646/phytotaxa.598.1.1 journal article 10.11646/phytotaxa.598.1.1 1179-3163 7958744 Cyathus prismaticus Z.Y. Duan & C.L. Zhao , sp. nov. Figs. 7–10 MycoBank no.: MB 845560 Etymology:— prismaticus (Lat.) referring to the narrow oblique prisms in the peridiole of the specimens. Holotype :— CHINA . Yunnan Province , Xishan District , Haikou Forest Park , E 102°61′ , N 24°79′ , on fallen branch of angiosperm, 16 September 2017 , CLZhao 2935 ( SWFC ). Fruiting body :— infundibuliform, obconical to cupulate, 7–12 mm in height, 4–6 mm in width at the mouth, non-expanding at the mouth and non-tapering towards the base; presence of the emplacement. exoperidium yellowish brown (5E4), shaggy or hirsute, external wall non-striate or only striate at near mouth, covered with pale yellow (4A3), irregular and flexible tufts of hair; hair hyphae with clamp connections, yellowish-brown (5E4), thick-walled (wall up to 0.5–2 μm thick), 1.5–9 µm in diameter. endoperidium silvery brown to dark brown (5E6–7F4), conspicuously striate with 0.3–0.8 mm between the groves. mouth finely fimbriate. peridium walls consist of three different layers: (1) outer wall layer: hyphal system dimitic, CB–, IKI–, tissues unchanged in KOH; generative hyphae with clamp connections, brown, slight thick-walled, frequently branched, 1.5–3.5 µm in diameter; skeletal hyphae colorless to yellowish-brown, thick-walled, unbranched, 1.5–3.5 µm in diameter; (2) inner wall layer: hyphal system dimitic, CB–, IKI–, tissues unchanged in KOH; generative hyphae with clamp connections, rreddish brown, slight thick-walled, frequently branched, 1.5–4.5 µm in diameter; skeletal hyphae reddish brown, thick-walled, unbranched, 2.5–4 µm in diameter;(3) pseudoparenchymatous layer. FIGURE 7. Basidiomata of Cyathus prismaticus . Bars: A = 1 cm, B = 1 mm (Holotype: CLZhao 2935). Photoplate by: Zi-Yan Duan. FIGURE 8. Peridiole of Cyathus prismaticus . Bars: A–B = 1 mm (Holotype: CLZhao 2935). Photoplate by: Zi-Yan Duan. FIGURE 9. Microscopic structures of Cyathus prismaticus (drawn from the holotype, CLZhao 2935). A: Outer wall of the peridium. B: Inner wall of the peridium. C: Three-layered peridium. D: Structure of the hair. Bars: A–D = 10 µm. Drawings by: Zi-Yan Duan. Peridioles : — shiny, slightly regular, elliptical-triangular, broadly ellipsoid to ovoid, brownish gray (7F2) to dark grey (8F1), surface irregular, wrinkled, tunica thin, brownish. cortex single-layered, 2–3 × 1.5–2.5 mm . funicular cord present, funiculus hyphae with clamp connections, thick-walled, branched, pale yellowish, 1–3 µm in diameter. hyphal system dimitic, hyphae CB–, IKI–, tissues unchanged in KOH; generative hyphae with clamp connections, colorless, thin-walled, branched, with oil drops inside, 0.5–5 µm in diameter; skeletal hyphae colorless, slight thick-walled, unbranched, with oil drops inside, 1–3 µm in diameter; narrow oblique prisms present. Basidiospores : — 8.5–20(–20.5) × 7.5–11 µm, L = 15.68 µm, W = 8.77 µm, Q = 1.8 (n = 60/1), subglobose, elliptical to broadly ellipsoid, rarely ovoid, colorless, smooth, thick-walled (up to 0.5–2 μm thick), CB–, IKI–, with inclusions or oil-like globule, without apiculus. Basidia not observed.