Lemon-chrome porecrust (Luteoporia flavula) similar to Luteoporia straminea and pointing crust (Xylodon subpunctus) similar to Xylodon punctus

NEWS - Lemon-chrome porecrust (Luteoporia flavula C.L. Zhao & H.M. Zhou, sp. nov.) similar to Luteoporia straminea and pointing crust (Xylodon subpunctus C.L. Zhao & H.M. Zhou, sp. nov.) similar to Xylodon punctus, two new species of wood-dwelling fungi were described from the Yunnan-Guizhou Plateau in southwest China.

Luteoporia F. Wu, Jia J. Chen & S.H. He. (2016) with Luteoporia albomarginata F. Wu, Jia J. Chen & S.H. He as the type species showed a monomitic hyphal system with generative hyphae containing clamp connections, and hyaline and smooth basidiospores.

Other species found in China are Luteoporia citriniporia Z.B. Liu & Yuan Yuan (2020), Luteoporia lutea (G. Cunn.) C.C. Chen & Sheng H. Wu (2021) and Luteoporia straminea C.L. Zhao (2023), while Luteoporia citriniporia is exclusively found in Europe, Luteoporia lutea is found in Oceania and the latter two species were originally described in southwest China.

Xylodon (Pers.) Gray (1821) is characterized by Xylodon quercinus (Pers.) (1821: 649) distributed in various habitats worldwide, including temperate, tropical and subtropical regions. A number of species have been reported in China.

Luteoporia flavula is characterized by purple tissue in KOH, in contrast to the reddish color of L. straminea. Basidiomata annual, resupinate, ceramic, odorless or tasteless when fresh, becoming hard when dry, up to 1 cm long, 1.2 cm wide, 200–250 μm thick when dry. Hymenophore odontoid, lemon chrome when fresh, curry yellow when dry, tissue turns purple in KOH. Sterile margin, narrow, and light lemon colored.

Generative hyphae monomitic with clamp joints, hyaline, thin to thick walled, IKI-, CB-. Subicular hyphae unbranched, 2.5–4 μm in diameter; subhymenial hyphae unbranched, 2–4 μm in diameter; abundant yellow to yellowish brown gelatinous substance present between subhymenium. Hymenial cystidia subuliform, hyaline, thick walled, 15.5–30 × 3.8–5.7 μm, no cystidioles; basidia 4-celled, clavate, with basal clamp joints, 24–29 × 4–5.2 μm.

Basidiospores oblong ellipsoid, hyaline, thin-walled, smooth, sometimes with guttules, IKI-, CB-, (3.4–)4–5.2(–5.5) × (2.2–)2.3–3.2(–3.4) μm, L = 4.56 μm, W = 2.74 μm, Q = 1.63–1.71 (n = 90/3).

Xylodon subpunctus differs from X. punctus in smaller basidiospores (2–4 × 1.5–2.5 μm vs. 5.5–7.2 × 2.5–3.6 μm). Basidiomata annual, regenerating, odorless and tasteless, keratinous when fresh, hard keratinous when dry, up to 4 cm long, 2 cm wide, 20–50 μm thick. Hymenium surface is powdery, shiny when dry, cracked. Sterile boundary is indistinct.

Hyphae monomitic, generative with clamp joints, hyaline, thin-walled, often branched, intertwined, IKI-, CB-, 1.8–4.4 μm in diameter; tissue unchanged in KOH; subhymenial hyphae densely covered by larger, irregular crystals; basal layer of hyphae arranged regularly.

Cystidia of two types: (1) occasional capitate cystidia, hyaline, thin-walled, slightly narrowed at the neck, with rounded apex, 27–34.2 × 3–3.5 μm; (2) fusiform cystidia often, hyaline, thin-walled, 20.3–26.8 × 5.3–6.4 μm; basidia 4-celled, stalked to clavate, with basal clamp connection, 10–17.4 × 2–5.2 μm

Basidiospores ellipsoid to oblong, hyaline, thin-walled, smooth, IKI-, CB-, (5.3–)5.5–7.2(–7.4) × (2.6–)2.5–3.6(–4.5) μm, L = 6.33 μm, W = 3.00 μm, Q = 2.08–2.13 (n = 60/2).

Original research

Hong-Min Zhou, Xin Yang, Yu-Yun Wang & Chang-Lin Zhao (2024). Morphological and molecular identification of two new wood-inhabiting macrofungi (Basidiomycota) from Yunnan-Guizhou Plateau, China. Phytotaxa 674 (1): 001–017, DOI:10.11646/phytotaxa.674.1.1

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