Clonostachys motuoensis S. C. He, K. D. Hyde & Q. Zhao 2025, sp. nov.

Clonostachys motuoensis S. C. He, K. D. Hyde & Q. Zhao sp. nov. Fig. 3 Etymology. The species epithet is derived from the location “ Motuo County ”, from where the holotype was collected. Typification. China • Xizang Autonomous Region, Linzhi City, Motuo County (29°11'N, 95°8'E, 1561 m), on the lower part of the leaves of Houttuynia cordata, July 27, 2022, collected by Hong-De Yang, YHD 669-1 (holotype: KUN-HKAS HKAS 133181); ex-type living culture: KUNCC 24-18530). GenBank: ITS: PQ 522506, 28 S: PQ 634393, tef 1: PQ 650479, tub 2: PQ 650461. Description. Sexual morph: Not observed. Asexual morph: Hyphomycetous. Colonies on the WA, solitary or gregarious, white to pale yellow, raised, dense, rough. Conidiophores mononematous, penicillate, straight or flexuous, branched at the apex, smooth, thin-walled, septate, hyaline, conidiophores produce globose cells at the apex, from globose to elongated or continue to differentiate, terminal branches developing into phialides, 94–146 × 2.5–4.7 μm (x ̄ = 125 × 3.5 μm, n = 20). Phialides monophialidic, terminal, flask-shaped, aseptate, hyaline, smooth, thin-walled, terminal developing into conidia, 9.1–18.7 × 2.3–3.5 μm (x ̄ = 13.2 × 2.8 μm, n = 20). Conidia amerospores, solitary, acrogenous, simple, ellipsoidal to oblong with obtuse ends, smooth, thin-walled, aseptate, hyaline, minutely guttulate, 3.9–5.6 × 2.5–3.3 μm (x ̄ = 4.6 × 2.9 μm, n = 30). Culture characteristics. Colonies on PDA reaching 3.5–4 cm after 20 days of incubation at 25 ° C, white both above and reverse, medium spare, raised, smooth, fimbriate, velvety, ciliate, not pigment produced. Habitat. Leaves of Houttuynia cordata. Additional material examined. China • Xizang Autonomous Region, Linzhi City, Motuo County (29°11'N, 95°8'E, 1561 m), on the lower part of the leaves of Houttuynia cordata, July 27, 2022, collected by Hong-De Yang, HSC 986 (isotype: KUN-HKAS 133182); ex-isotype living culture: KUNCC 24-18531). GenBank: ITS: PQ 522507, 28 S: PQ 634394, tef 1: PQ 650480, tub 2: PQ 650462. Notes. In the phylogenetic analysis, Clonostachys motuoensis clustered sister to C. linzhiensis and C. aranearum (Fig. 1). Morphologically, our specimen (HKAS 133181 and HKAS 133182) has larger conidiophores (L / W ratio: 35 vs 12) and longer phialides (L / W ratio: 4.7 vs 6.7) in comparison to C. aranearum. Clonostachys motuoensis differs from C. aranearum by 6 / 544 (1 %) ITS and 4 / 294 (1.3 %) tub 2 differences in the nucleotides. It is worth noting that C. aranearum is parasitic on spiders, while C. motuoensis is endophytic on Houttuynia cordata leaves. In addition, C. aranearum was collected from Qian Ling Shan Park, Guiyang City, Guizhou Province, China, with an altitude of 1100–1369 m, belonging to a plateau subtropical climate (Wan et al. 2016). Clonostachys motuoensis was collected from Motuo County, Linzhi City, Xizang Autonomous Region, China, with an altitude of 1561 m, belonging to a tropical rainforest climate. Based on these distinctions and following the guidelines of Maharachchimbukura et al. (2021), we identified our specimen as a new species, C. motuoensis.