Phaeoclavulina qinghaiensis Y. Shan & S. Y. Liu 2026, sp. nov.

Phaeoclavulina qinghaiensis Y. Shan & S. Y. Liu sp. nov. Fig. 3 Etymology. Qinghaiensis (Latin) refers to the type location, Qinghai Province, China. Diagnosis. Basidiomata yellow to orange-yellow, not changing color when bruised. Basidiospores are broadly ellipsoid to oblong and exhibit a dense covering of spherical to irregular warts. Type. China • Qinghai Province, Xining City, Datong County, 37°04'21"N, 101°49'04"E, alt. 2865 m, 11 September 2024, Yong Shan, Shu-Yan Liu, Xue-Lian Wu, Sheng-Bang Zhang, Wan-Lin Zhao and De-Ning Zhang, HMJAU 60997, holotype. GenBank: nuc rDNA ITS 1-5.8 S-ITS 2 = PV 821748; nuc rDNA 28 S = PV 822041. Basidiomata. Arising from soil or moss-covered coniferous forest floor, typically gregarious or caespitose, erect, and distinctly coralloid in form, measuring (26 –) 30–60 (– 63) × (6 –) 10–20 (– 21) mm. Main branches thick, originating from a short stipe-like base and successively divided dichotomously or polychotomously, typically 4–5 times, with apices subacute, commonly forked or slightly recurved, measuring approximately 1.5–4 mm in length. Fresh basidiomata yellow to orange-yellow overall, paler at the base and slightly darker at the tips; color unchanging when bruised or injured. Surface dry, without gelatinous or tomentose covering; texture fleshy to firm. Stipe short and inconspicuous, central or slightly eccentric, often merging with the basal branches. In some specimens, basal stipe structures laterally connate, with distinct longitudinal grooves at the points of fusion, forming deeply embedded junctions. Basal parts frequently associated with rhizomorphic strands, sometimes bearing remnants of moss, pine needles, or cone scales. Upon drying, basidiomata dark brown to yellowish brown, with slight surface shrinkage but well-preserved branching structure; base pale yellowish white to light brown, with slightly fibrous texture. Micromorphology. Basidia 39.1–50.9 × 5.9–9.1 μm, slightly granular upon maturation, hyaline to faintly yellowish, bearing four sterigmata. Hyphal system monomitic; hyphae septate, with clamp connections; contextual hyphae (1.8 –) 2–5 μm wide, with variable wall thickness, branched, densely arranged. Basidiospores (6.5 –) 8.4–8.9 (– 11.0) × (3.5 –) 4.8–5.3 (– 6.7) μm [Q = 1.19–2.31, Qm = 1.74 ± 0.27], broadly ellipsoid to oblong, slightly inequilateral, more or less rounded at one end and narrower and slightly prolonged at the other; surface distinctly roughened. Some spores contain one to several guttules. Under SEM, spores exhibit a dense covering of warty (verrucose) ornamentation. These ornamentations are spherical to irregular in shape, moderately sized (0.1–0.5 µm in diameter), evenly distributed, and do not coalesce into ridges or reticulate structures. Notes. Phaeoclavulina qinghaiensis formed as sister to P. abietina in the phylogenetic analyses, but the two species can be distinguished by several morphological characters. Basidiomata of P. qinghaiensis remain unchanged in color when bruised or injured, whereas the flesh of P. abietina becomes slightly ochraceous when cut. Basidiospores of P. qinghaiensis are broadly ellipsoid to oblong and often slightly inequilateral, while those of P. abietina are elongate and pip-shaped. In addition, differences are observed in basidiospore ornamentation: basidiospores of Phaeoclavulina qinghaiensis are verrucose, with spherical to irregular ornamentation that are evenly distributed and of moderate size (0.1–0.5 μm in diameter), whereas basidiospores of P. abietina bear closely echinulate ornamentation composed of short, acute, hyaline spines 0.5 μm long, or 0.5–1 μm long in other collections. Additional materials examined. China • Qinghai Province, Xining City, Datong County, 37°04'21"N, 101°49'04"E, alt. 2860 m, 11 September 2024, Yong Shan, Shu-Yan Liu, Xue-Lian Wu, Sheng-Bang Zhang, Wan-Lin Zhao and De-Ning Zhang, HMJAU 60998, paratype. GenBank: nuc rDNA ITS 1-5.8 S-ITS 2 = PV 821749; nuc rDNA 28 S = PV 822042. Habit and distribution. Gregarious on the soil around Picea crassifolia. Known only from the type locality in Qinghai Province, China.