taxonID	type	description	language	source
03AD8904CD66F45DFF6CFF51FC277837.taxon	etymology	Etymology: — The epithet “ motuoense ” refers to the location “ Motuo, China ” from where the holotype specimen was collected.	en	Lei, Lei, Luangharn, Thatsanee, Yu, Feng-Ming, Zhao, Qi (2025): Two new species of Pseudohydnum (Auriculariales, Basidiomycota) from the Qinghai-Tibet Plateau in China. Phytotaxa 690 (2): 243-254, DOI: 10.11646/phytotaxa.690.2.5, URL: https://doi.org/10.11646/phytotaxa.690.2.5
03AD8904CD66F45DFF6CFF51FC277837.taxon	diagnosis	Diagnosis: — Pseudohydnum motuoense is morphologically very similar to P. meridianum, however, the former has a longer and thicker stipe that is often expanded at the base.	en	Lei, Lei, Luangharn, Thatsanee, Yu, Feng-Ming, Zhao, Qi (2025): Two new species of Pseudohydnum (Auriculariales, Basidiomycota) from the Qinghai-Tibet Plateau in China. Phytotaxa 690 (2): 243-254, DOI: 10.11646/phytotaxa.690.2.5, URL: https://doi.org/10.11646/phytotaxa.690.2.5
03AD8904CD66F45DFF6CFF51FC277837.taxon	materials_examined	Holotype: — CHINA, Xizang, Linzhi, Motuo, 29.32675317 ° N, 95.35616065 ° E, alt. 1,705 m, 10 Jul. 2022, coll. Lei Lei, LEI- 477 (KUN-HKAS 134347) Basidiomata small to medium-sized, tapering upwards when young. Pileus 20 – 55 mm diam, gradually unfolds after maturity, irregular shell-shaped to kidney-shaped; surface velutinous or mastoid, reddish brown (8 E 6) to dark brown (8 F 8) when fresh and dark brown (8 F 8) to black when dried, gelatinous when fresh, brittle when dried. Spines up to 2 − 5 mm long, 3 − 4 per mm at the base, conical, white when fresh, and white with pale green (29 A 4) tinges when dried. Context 4 – 6 mm thick, translucent, unchanging colour when injured, resilient. Stipe 30 – 60 × 6 – 20 mm, lateral, gelatinous, translucent, velutinate, cylindrical, sometimes laterally compressed, often expanding at the base and sometimes expanding towards the apex, surface concolourous to pileus surface or paler. Basidiospores (5.0 –) 5.5 – 6.8 (– 7.5) × (4.0 –) 4.6 – 6.0 (– 6.5) μm, L m = 6.1 μm, W m = 5.3 μm, Q = 1.06 – 1.22 (n = 100 / 5 / 5), Q m = 1.21 ± 0.08, broadly ellipsoid to subglobose, hyaline, thin-walled, with a big guttule. Probasidia 8.0 − 10.0 × 10.5 − 14.0 μm, fusiform to lageniform. Hyphidia 1.5 − 2.5 μm wide, occasionally branched. Basidia 8.0 − 10.7 × 9.4 − 15.0 μm, four-celled, barrel-shaped, globose to subglobose, with guttules; sterigmata up to 10.5 × 2 − 3 μm. Contextual hyphae 1.5 − 4.0 μm wide, frequently branched, interwoven, thin- to slightly thick-walled, hyaline. Tramal hyphae 2.0 − 6.0 μm wide, frequently branched, interwoven, thin-walled, hyaline. Pileipellis is composed of subparallel or ascending hyphae, 2.0 – 8.0 μm wide, slightly inflated, thin- or slightly thick-walled, hyaline. Clamps are common in all parts of basidiomata.	en	Lei, Lei, Luangharn, Thatsanee, Yu, Feng-Ming, Zhao, Qi (2025): Two new species of Pseudohydnum (Auriculariales, Basidiomycota) from the Qinghai-Tibet Plateau in China. Phytotaxa 690 (2): 243-254, DOI: 10.11646/phytotaxa.690.2.5, URL: https://doi.org/10.11646/phytotaxa.690.2.5
03AD8904CD66F45DFF6CFF51FC277837.taxon	description	Habitat: — Gregarious, growing on rotten wood in mixed forest with trees of Elaeocarpus, Exbucklandia, and Myrsine.	en	Lei, Lei, Luangharn, Thatsanee, Yu, Feng-Ming, Zhao, Qi (2025): Two new species of Pseudohydnum (Auriculariales, Basidiomycota) from the Qinghai-Tibet Plateau in China. Phytotaxa 690 (2): 243-254, DOI: 10.11646/phytotaxa.690.2.5, URL: https://doi.org/10.11646/phytotaxa.690.2.5
03AD8904CD66F45DFF6CFF51FC277837.taxon	materials_examined	Additional material examined: — CHINA, Xizang, Linzhi, Motuo, 29.32675317 ° N, 95.35616065 ° E, alt. 1,705 m, 10 Jul. 2022, coll. Lei Lei, LEI- 479 (KUN-HKAS 134348); coll. Shu-Xin Bao, Bao 190 (KUN-HKAS 134351); coll. Li-Heng Mu, mu 320 (KUN-HKAS 134349); coll. Feng-Ming Yu, FM 22 - 196 (KUN-HKAS 134350). Notes: — Pseudohydnum motuoense is characterized by small to medium-sized basidiomata, shell- to kidney-shaped pileus with reddish brown to dark brown surface, stipe often expanding at the base, and broadly ellipsoid to subglobose basidiospores. It is very similar to P. meridianum in micro-morphological characteristics, such as basidiospores size, the wide pileipellis hyphae, and sterigmata. However, the latter has a shorter and thinner stipe (20 × 5 mm) that gradually tapes to the base (Spirin et al. 2023). Pseudohydnum motuoense shares similar morphological characteristics with P. brunneiceps but is distinguished by having shorter basidiospores (5.5 – 6.8 vs. 6.0 – 8.0 μm, Chen et al. 2020). In addition, P. motuoense grows on decaying wood in broad-leaved forests, while P. brunneiceps grows on decaying gymnosperm wood dominated by Cryptomeria japonica (Chen et al. 2020). Pseudohydnum motuoense exhibits characteristics similar to P. brunneovelutinum such as a dark brown and velutinous pileus and broadly ellipsoid to subglobose basidiospores. Pseudohydnum brunneovelutinum was originally described in Brazil. This species has shorter stipe (up to 15 mm), narrower hyphae on the pileal surface (2.5 – 5 μm), and spine tramal hyphae (1.5 – 2.8 μm, Coelho-Nascimento et al. 2024). Additionally, P. umbrosum, a species that also has a toned pileus surface from Asia, but differs in several key features. It has a very short or absent stipe and larger basidia (12.2 – 15.8 × 9.1 – 12.2 μm) and basidiospores (7.6 – 9.8 × 6.0 – 7.1 μm) compared to P. motuoense (Spirin et al. 2023). Phylogenetically, the newly identified taxon, P. motuoense, forms a well-supported clade (MLBP = 94, BIPP = 1.00) and is categorized as a successive sister clade to both P. meridianum and P. brunneiceps (Fig. 1).	en	Lei, Lei, Luangharn, Thatsanee, Yu, Feng-Ming, Zhao, Qi (2025): Two new species of Pseudohydnum (Auriculariales, Basidiomycota) from the Qinghai-Tibet Plateau in China. Phytotaxa 690 (2): 243-254, DOI: 10.11646/phytotaxa.690.2.5, URL: https://doi.org/10.11646/phytotaxa.690.2.5
03AD8904CD66F450FF6CF8C9FBA37EBC.taxon	etymology	Etymology: — The epithet “ purum ” refers to the pure white basidiomata.	en	Lei, Lei, Luangharn, Thatsanee, Yu, Feng-Ming, Zhao, Qi (2025): Two new species of Pseudohydnum (Auriculariales, Basidiomycota) from the Qinghai-Tibet Plateau in China. Phytotaxa 690 (2): 243-254, DOI: 10.11646/phytotaxa.690.2.5, URL: https://doi.org/10.11646/phytotaxa.690.2.5
03AD8904CD66F450FF6CF8C9FBA37EBC.taxon	diagnosis	Diagnosis: — Pseudohydnum purum is similar to P. viridimontanum small-sized and whitish basidiomata, but can be distinguished from P. purum by its smaller basidiospores and presence of cylindrical to fusiform inflated elements in the spine tramal hyphae.	en	Lei, Lei, Luangharn, Thatsanee, Yu, Feng-Ming, Zhao, Qi (2025): Two new species of Pseudohydnum (Auriculariales, Basidiomycota) from the Qinghai-Tibet Plateau in China. Phytotaxa 690 (2): 243-254, DOI: 10.11646/phytotaxa.690.2.5, URL: https://doi.org/10.11646/phytotaxa.690.2.5
03AD8904CD66F450FF6CF8C9FBA37EBC.taxon	materials_examined	Holotype: — CHINA, Xizang, Rikaze, Dingjie, 27.91598793 ° N, 87.36751710 ° E, alt. 2,933 m, 04 Jul. 2022, coll. Lei Lei, LEI- 426 (KUN-HKAS 134352). Basidiomata small-sized, tapering upwards when young. Pileus 10 – 20 mm diam, gradually unfolds after maturity, irregular sucker-like; surface velutinous or mastoid, white when fresh and pale olive-brown (4 D 4) or light brown (5 D 4) when dried, gelatinous when fresh, brittle when dried. Spines when dried up to 0.5 mm long and 6 − 10 per mm at the base, conical, white when fresh, and pastel yellow (2 D 5) to buff olive (2 A 4) when dried. Context 1 – 2 mm thick, translucent, unchanging colour when injured, resilient. Stipe 15 – 25 × 8 – 13 mm, lateral, flat-cylindrical to cylindrical, gelatinous, translucent, velutinate, surface concolourous with pileus surface. Basidiospores: (6.5 –) 7.0 – 8.5 (– 9.0) × (5.5 –) 6.0 – 7.5 (– 8.0) μm, L m = 7.5 μm, W m = 6.7 μm, Q = 1.07 – 1.19 (n = 60 / 3 / 2), Q m = 1.13 ± 0.06, broadly ellipsoid to subglobose, hyaline, thin-walled, with a big guttule. Probasidia 11.8 − 16.4 × 8.9 − 13.3 μm, fusiform to lageniform. Hyphidia 1.5 − 3 μm wide, occasionally branched. Basidia 9.6 − 14.9 × 11.0 − 14.4 μm, four-celled, barrel-shaped, globose to subglobose, with guttules, sterigmata up to 17 × 1.4 − 3.3 μm. Contextual hyphae 1.5 − 5.5 μm wide, frequently branched, interwoven, thin- to slightly thick-walled, hyaline. Tramal hyphae 1.5 − 4.0 μm wide, frequently branched, interwoven, thin-walled, hyaline. Pileipellis is composed of subparallel or ascending hyphae, 2.0 – 4.5 μm wide, interwoven, thin- or slightly thick-walled, hyaline. Clamps are common in all parts of basidiomata.	en	Lei, Lei, Luangharn, Thatsanee, Yu, Feng-Ming, Zhao, Qi (2025): Two new species of Pseudohydnum (Auriculariales, Basidiomycota) from the Qinghai-Tibet Plateau in China. Phytotaxa 690 (2): 243-254, DOI: 10.11646/phytotaxa.690.2.5, URL: https://doi.org/10.11646/phytotaxa.690.2.5
03AD8904CD66F450FF6CF8C9FBA37EBC.taxon	description	Habitat: — Solitary or gregarious, growing on rotten wood in theropencedrymion, mainly include: Pinus, Rhododendron, Sorbus, Taxus, Toxicodendron, and Viburnum.	en	Lei, Lei, Luangharn, Thatsanee, Yu, Feng-Ming, Zhao, Qi (2025): Two new species of Pseudohydnum (Auriculariales, Basidiomycota) from the Qinghai-Tibet Plateau in China. Phytotaxa 690 (2): 243-254, DOI: 10.11646/phytotaxa.690.2.5, URL: https://doi.org/10.11646/phytotaxa.690.2.5
03AD8904CD66F450FF6CF8C9FBA37EBC.taxon	materials_examined	Additional material examined: — CHINA, Xizang, Rikaze, Dingjie, 27.91598793 ° N, 87.36751710 ° E, alt. 2,933 m, 04 Jul. 2022, coll. Feng-Ming Yu, FM 22 - 425 (KUN-HKAS 134353). Notes: — Pseudohydnum purum is characterized by small-sized basidiomata, irregular and sucker-like pileus with a white surface, flat-cylindrical white stipe, and broadly ellipsoid to subglobose basidiospores. Morphologically, P. purum resembles P. cystidiatum, P. translucens, and P. viridimontanum on the small-sized and whitish basidiomata. However, P. purum differs from P. cystidiatum in that the latter has a very short or absent stipe and the presence of cystidia (Spirin et al. 2023). Pseudohydnum viridimontanum can be distinguished from P. purum by its smaller basidiospores (5.6 – 6.9 × 4.3 – 5.0), and the presence of cylindrical to fusiform inflated elements in the spine tramal hyphae (Coelho-Nascimento et al. 2024). In contrast to P. purum, P. translucens (5.4 – 7.4 × 4.2 – 6.9 μm) has smaller spores (Zhou et al. 2023). In the LSU + ITS phylogenetic tree (Fig. 1), P. purum forms a well-supported clade (MLBP = 100, BIPP = 1.00) and is grouped as a sister clade to P. viridimontanum with a more substantial support value (MLPP = 100, BIPP = 1.00), and occupied a basal position within the genus Pseudohydnum.	en	Lei, Lei, Luangharn, Thatsanee, Yu, Feng-Ming, Zhao, Qi (2025): Two new species of Pseudohydnum (Auriculariales, Basidiomycota) from the Qinghai-Tibet Plateau in China. Phytotaxa 690 (2): 243-254, DOI: 10.11646/phytotaxa.690.2.5, URL: https://doi.org/10.11646/phytotaxa.690.2.5
