Calostoma sinocinnabarinum N. K. Zeng, Chang Xu & Zhi Q. Liang 2022, sp. nov.

Calostoma sinocinnabarinum N.K. Zeng, Chang Xu & Zhi Q. Liang, sp. nov. (Figs. 2d–f, 4, 5d–f) MycoBank: MB841417 Etymology:—Latin “ sin -” meaning China, holotype locality; “ cinnabarinum ” meaning the surface of peridium colored with a red tint. Diagnosis:—Characterized by a gelatinous, orange-red to fiery red peridium, a pale orange stipe, broadly ellipsoid basidiospores with prominent reticulations, and a distribution in Asia. Holotype:— CHINA. Hunan Province: Yizhang County, Mangshan National Nature Reserve, 112°93′21″E, 24°95′67″71 N, elev. 1200 m, 29 July 2019, N. K. Zeng 4157 (FHMU3739). GenBank accession numbers: 28 S = OK147440, ITS = OK157459. Description:— Basidiomata stalked. Peridium subglobose or globose, 1.5–2.5 cm in diam. Exoperidium gelatinous, hyaline, with jelly-like and seed-like appendages when mature, finally falling off. Mesoperidium reddish orange (6A7) when young, then pale brown; surface nearly smooth, then cracked into irregular blocky lobes, finally falling off. Endoperidium red (6B8) to fiery red, velvet. Ostiolum vermilion (9B7), with upraised ridges, star-shaped, teeth 5–8, covered by the exoperidium and mesoperidium when young, exposed when mature. Stipe strongly developed, central, up to 1.8 cm long, about 2 cm wide, consisting of many lines extending from the bottom of the peridium and wrapped by the colloidal exoperidium. Basidiospores [220/11/4] 10–15(–16) × (8.5–)9–12(–13) μm, Q = (1.00–)1.04–1.50(–1.61), Qm = 1.25 ± 0.14 (including ornamentation), [220/11/4] (7–)8–13(–13.5) × (6–)6.5–9(–9.5) μm, Q = (1.00–)1.06–1.63 (–1.86), Qm = 1.34 ± 0.19 (excluding ornamentation), broadly ellipsoid, with prominent reticulations, hyaline to pale yellow in KOH. Basidia not seen, disintegrating when mature. Exoperidium hyphae long, sparsely branched, gelatinized, hyaline to yellowish in KOH; terminal cells 12–85 × 2–3 μm, thick-walled (1–2 μm). Mesoperidium hyphae yellowish brown in KOH, occasionally branched, with yellowish brown, granular appendages; terminal cells 15–50 × 5–7 μm, slightly thick-walled (0.7–0.9 μm). Stipe hyphae composed of two layers; hyphae in the first layer lemon yellow, with terminal cells measuring 30–65 × 5–8.5 μm, thick-walled (1.5–2 μm); hyphae in the second layer hyaline to pale yellow, with terminal cells measuring 12–49 × 2–4 μm, slightly thick-walled (about 0.4 μm). Clamp connections observed in exoperidium hyphae and the second layer of stipe hyphae. Habitat:—Gregarious on dark brown soil (pH 5.5) in mixed forests of Lithocarpus spp. and Pinus kwangtungensis Chun ex Tsiang. Known distribution:—Central China (Hunan Province); eastern China (Jiangxi Province). Additional specimens examined:— CHINA. Hunan Province: Yizhang County, Mangshan National Nature Reserve, elev. 1200 m, 20 July 2013, S. Z . Huang s.n. (FHMU1007); same location, 29 July 2019, N. K . Zeng 4164, 4167 (FHMU3732, 3818). Jiangxi Province: Wuyi Mountain, Tongmuguan, elev. 1080 m, 14 October 1993, M . Zang s.n. (HKAS27132).Published as part of Xu, Chang, Liang, Zhi-Qun, Jiang, Shuai, Zhang, Ping, Huang, Sheng-Zhuo & Zeng, Nian- Kai, 2022, Notes on two species of Calostoma (Calostomataceae, Boletales) from the south of China, pp. 49-61 in Phytotaxa 533 (1) on pages 57-58, DOI: 10.11646/phytotaxa.533.1.2, http://zenodo.org/record/597388