Crinipellis macrospora T. Bau & W. N. Hou 2026, stat. nov.

Crinipellis macrospora (Antonín, Ryoo & H. D. Shin) T. Bau & W. N. Hou stat. nov. Figs 14 A – C, 15 Basionym. Crinipellis nigricaulis var. macrospora Antonín, Ryoo & H. D. Shin, Mycotaxon 108: 431. 2009. Description. Basidiomata small. Pileus 0.4–1.1 cm diam., convex, centrally depressed and disc-shaped, with a single protuberance in the disc; surface cream (RAL 9001), with shallow grooves at the margin, covered with beige-brown (RAL 8024), tomentose scales arranged radially; central depression brown (RAL 8002), lacking concentric zones. Context cream (RAL 9001), thin; odor indistinct. Lamellae free, moderately dense, unequal, L = 18–20, I = 1–2, cream (RAL 9001). Stipe 4–15 cm long, 0.1 cm thick, central, extremely long, cylindrical, equal; base blackish-brown (RAL 8022), gradually lightening upwards, apex cream (RAL 9001), slightly enlarged; surface minutely tomentose; base with rhizomorphs. Basidiospores (7) 7–9.5 (10.3) × (3.1) 3.5–4.9 (5.8) µm, Q = (1.55) 1.79–2.44 (3) [2.07 ± 0.27], oblong-ellipsoid, smooth, thin- to slightly thick-walled, hyaline, containing oil droplets, inamyloid. Basidia 15–26 × 3.4–7 µm, clavate, thin-walled, hyaline, 4 - (rarely 2 -) sterigmate; sterigmata 1.4–4.3 µm long, inamyloid. Basidioles 17–25 × 4–6.8 µm, clavate to fusiform, thin-walled, hyaline, inamyloid. Cheilocystidia clustered, 14–22 × 4–8.6 µm; main body subcylindrical to clavate, thin-walled, hyaline; apex bearing 4–6 branches, branches 4–12 × 1–3 µm. Pleurocystidia not observed. Lamellar trama regular. Pileus trama a cutis, brown in water, unchanged in 5 % KOH; terminal cells dextrinoid. Pileus hairs 136–375 × 6–9 µm, cylindrical, setose, thick-walled, dextrinoid, brown in water, unchanged in 5 % KOH, with rare and inconspicuous secondary septa. Stipe hairs 65–299 × 2.6–5.4 µm, cylindrical, setose, thick-walled. Stip trama composed of cylindrical cells 3.7–6.9 µm wide, appearing emerald green in KOH. Clamp connections present. Typus. Republic of Korea • Chuncheon, Dongsan-myeon, Bongmyeong-ri, 22. VI 1 I. 2007, leg. V. Antonin 07.96 et R. Ryoo (holotypus in herbario BRNM 712569 preservatur). Materials examined. CHINA • Jilin Province, Jilin City, Huadian City, Hongshi National Forest Park, on leaf litter in broad-leaved forests, 27 August 2023, 42°49'44"N, 127°08'49"E, alt. 465 m, T. Bau & S. Y. Li, FJAU 69423 (L 23082707). • Jilin Province, Baishan City, Fusong County, Songjianghe National Forest Park, on leaf litter in broad-leaved forests, 13 July 2024, 42°10'17"N, 127°30'52"E, alt. 762 m, J. L. Wei, FJAU 69421 (J 24071308). • Liaoning Province, Dalian City, Zhuanghe City, Tianmenshan National Forest Park, on leaf litter in broad-leaved forests, 7 July 2024, 40°09'51"N, 122°54'05"E, alt. 267 m, W. N. Hou, FJAU 69422 (H 2470708). Notes. Based on the phylogenetic tree constructed in this study, sequences of the collected specimens FJAU 69421, FJAU 69422 and FJAU 69423 cluster with those of Cr. nigricaulis var. macrospora. Cr. nigricaulis var. macrospora was described by Antonín et al. based on the holotype BRNM 712569 (Korea) (Antonín et al. 2009). According to the original description, Cr. nigricaulis var. macrospora is characterized by a small pileus that is entirely brown to dark brown and later whitish at the margin, a very long filiform stipe, and moderately large basidiospores [8.5–11.5 × 3.75–4.75 (– 5.0) µm], as well as clavate, (sub) cylindrical to subfusoid cheilocystidia bearing digitate projections up to 8 (– 10) × 2.0 µm with obtuse to subacute apices (Antonín et al. 2009). Overall, the examined material aligns closely with the original description in all observed morphological characters. However, the KOH reaction of pileus hairs exhibits minor differences between the two groups. The pileus hairs of the examined specimens remain brown in 5 % KOH. The hairs do not turn green. However, the original description reported an olive-green color change in pileus hairs in KOH. The cause of the aforementioned discrepancy requires further investigation. Combined with phylogenetic evidence, these specimens are deemed conspecific. Antonín et al. (2009) stated that Cr. nigricaulis var. macrospora (E = 2.2–3.0, Q = 2.4–2.6, cheilocystidia 12–20 × 4–7 μm) differs from Cr. nigricaulis var. nigricaulis (E = 1.6–2.2, Q = 1.8–1.9, cheilocystidia 15–23 × 6–11 μm) (Takahashi 2000) primarily in the E and Q values of the basidiospores and the width of the cheilocystidia. Here, E represents the quotient of length and width of an individual spore. Beyond these documented differences, reevaluation of Takahashi’s original description of Cr. nigricaulis, combined with the material examined in the present study, reveals several additional morphological characters that support their taxonomic separation. Cr. nigricaulis possesses a slightly umbilicate pileus center, radially fibrillose-strigose surface scales along plicate ridges, and pileus hairs with secondary septa that form scalariform structures. Phylogenetic analysis further demonstrates that Cr. nigricaulis var. macrospora and Cr. nigricaulis form two distinct, well-supported clades. Therefore, the elevation of Cr. nigricaulis var. macrospora to species rank is validated (Takahashi 2000). This species is sister to Cr. cupreostipes. Morphologically, this species (stipe hairs 65–299 µm long) differs from (stipe hairs 72–160 µm long, as reported in the protologue) in the length range of the stipe hairs (Kerekes and Desjardin 2009; Dutta et al. 2015). Although their ranges partially overlap, this character can currently be used to distinguish the two species. Further evidence is needed to identify and evaluate additional diagnostic characters.