Sebacina caducifoliicola H. Suh, D. Kim & Y. W. Lim 2026, sp. nov.

Sebacina caducifoliicola H. Suh, D. Kim & Y. W. Lim sp. nov. Fig. 5 Diagnosis. Sebacina caducifoliicola grows on litter and plant materials lying on the ground, and its tip grows in a frost pattern. Holotype. REPUBLIC OF KOREA, Gangwon State, Yanggu-gun, Yanggu-eup, Yanggu Arboretum, on a litter and plant materials lying on the ground, 17 August 2023. SFC 20230817-41 (dried specimen). Etymology. From caducifolia – fallen leaves and cola – living in Latin, referring to the basidiomata growing on litter. Description. Basidiomata fully resupinate, attached firmly to the substrate of litter and plant materials on the ground, growing on soil, forming thick patches several centimeters. Surface smooth, puffy when young, soft to undulate to tuberculate, dull, white (1 A 1) to yellowish white (4 A 2), consistency wax-like, cartilaginous when old. Margin growing in a sharp, frost pattern, slightly fibrillose. Basal hyphal system monomitic, hyaline, 2.5–4.0 μm in diameter, septate without clamps, thick-walled up to 1 μm thick. Basidiospores broadly elliptical to oval, hyaline, smooth, IKI-, CB-, (7.6 –) 8.1–10.0 (– 10.8) × (5.2 –) 5.6–6.0 (– 6.7) μm, with granular contents (L = 9.4 μm, W = 6.5 μm, Q = 1.4, n = 32 / 2). Resting spores occasionally observed, thick-walled, irregularly shaped. Dikaryophyses coralloid, flagelliformed, and ramified, partially derived from the same hyphae with basidia. Probasidia subglobose or pyriform, mature basidia globose, longitudinally septate, 11.0–13.5 × 9.5–10.5 μm, usually containing oil drops, with four elongated sterigmata, average 2 μm width, up to 24 μm long, blunt at the apex. Cystidia absent. Distribution. REPUBLIC OF KOREA. Additional specimens examined. REPUBLIC OF KOREA, Seoul, Gwanak-gu, Mt. Gwanak, on a litter and plant materials lying on the ground, 04 July 2023, SFC 20230704-04; REPUBLIC OF KOREA Seoul, Gwanak-gu, Mt. Gwanak, on a litter and plant materials lying on the ground, on a litter and plant materials lying on the ground, 04 July 2023, SFC 20240704-05; REPUBLIC OF KOREA, Gangwon State, Yanggu-gun, Yanggu-eup, Yanggu Arboretum, on fallen leaves and litter, 17 August 2023, SFC 20230817-45. Notes. Sebacina caducifoliicola is phylogenetically close to S. pseudocandida. However, S. caducifoliicola can be distinguished from S. caducifoliicola by the absence of upright basidiomata, which are present in the latter (Oberwinkler et al. 2014). Furthermore, S. caducifoliicola differs from S. pseudocandida by 51 nucleotide positions across three genetic regions (ITS: 20 bases; LSU: 11 bases; rpb 2: 20 bases), supporting its recognition as a distinct species. GenBank accession numbers. ITS (PV 399930 – PV 399931, PV 399940, PV 399942), LSU (PV 399892 – PV 399893, PV 399902, PV 399904), rpb 2 (PV 417273 – PV 417276).