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

Sebacina crystallina H. Suh, D. Kim & Y. W. Lim sp. nov. Fig. 6 Diagnosis. Basidiomata form sharp and wax-like edges on the substrate. Holotype. REPUBLIC OF KOREA, Gangwon State, Mt. Taebaek National Park, Baekcheon Valley, on dead branches and trunk of the tree, 19 September 2019. SFC 20190919-11 (dried specimen). Etymology. From crystallus – crystal in Latin, referring to the crystal-shaped basidiomata. Description. Basidiomata fully resupinate, attached firmly to the substrate, encrusting small branches and the base of living plants, forming thick patches several centimeters long. Surface smooth to undulate-tuberculate, dull, white (1 A 1), yellowish white (4 A 2) to light yellow (4 A 4) on the center, consistency wax-like, cartilaginous. Margin growing round and distinctly bounded. Basal hyphal system monomitic, hyaline, 2.5–4.5 μm in diameter, septate without clamps, thick-walled up to 0.9 μm thick. Basidiospores broadly elliptical to oval, occasionally germinating by repetition, hyaline, smooth, IKI-, CB-, (7.1 –) 8.5–12.7 (– 14.2) × (4.9 –) 5.2–6.9 (– 7.2) with granular contents (L = 10.9 μm, W = 5.8 μm, Q = 1.8, n = 57 / 2). Dikaryophyses simple-structured, flagelliformed, derived from the same hyphae with basidia. Probasidia elliptical to pyriform, usually with lateral hyphal branches, mature basidia subglobose to pyriform, longitudinally septate, 13.1–14.1 × 9.2–10.6 μm on average, usually containing oil drops, with four elongated sterigmata, average 3 μm width, up to 36 μm long, blunt to tapered at the apex. Cystidia absent. Distribution. REPUBLIC OF KOREA, RUSSIAN FEDERATION. Additional specimens examined. RUSSIAN FEDERATION, Primorskiy kray, Vitiaz’ settlement, Gamov Peninsula, on a plant litter, 16 August 2017, NIBRFG 0000504700; REPUBLIC OF KOREA, Seoul, Gwanak-gu, Seoul National University, on a trunk of a tree, 29 July 2023, SFC 20230729-09. Notes. Sebacina crystallina is phylogenetically closely related to Sebacina schweinitzii. Morphologically, the two species share spathulate to clavarioid basidiomata and thick-walled hyphae. However, they can be distinguished by their hymenial surfaces: S. crystallina exhibits an opaque, dull, white (1 A 1) hymenium, whereas S. schweinitzii has a transparent, smooth surface (Oberwinkler et al. 2014). The two species also exhibit regional differences; S. crystallina is found in East Asia, whereas S. schweinitzii occurs in Europe. GenBank accession numbers. ITS (PV 399921, PV 399927, PV 399934), LSU (PV 399884, PV 399890, PV 399896), rpb 2 (PV 417271 – PV 417272).