Candolleomyces subsingeri (T. Bau & J.Q. Yan) D. Wächt. & A. Melzer, Mycol. Progr. 19(11): 1234 (2020)
Index Fungorum number: IF 832282; MycoBank number: MB 832282; Facesoffungi number: FoF 16383; Figs. 1, 2, 3
Pileus 15–35 mm, paraboloid to campanulate, with obtuse umbo at the disc, hygrophanous, grayish orange to orange gray (5B3–5B2) becoming brown-orange (6C4–6C3) with maturity, surface fibrillose, with minute velar squamules scattered throughout, prominent at the young stage, dense at the center, striate indistinct, margin irregular, appendiculate when young. Lamellae adnate, grayish orange (6B4), 3–4 mm broad, close with lamellulae of 2–3 tiers, edges serrated, white (6A1). Stipe 30–48 × 2–3 mm, cylindrical, hollow, equal, slightly tapering towards apex, fragile, slightly covered with white fibrils. Odor and taste indistinctive.
Basidiospores 5.98–7.2–7.98(–8.6) × 4.8–5.1–5.4(–5.7) µm, Q = 1.2–1.4–1.52, ellipsoid, very pale, slightly yellowish in 5% KOH, smooth, germ pore absent. Basidia 16.24–20 × 7.1–9.2 µm, 4- or 2-spored, clavate, hyaline, thin-walled. Pleurocystidia absent. Cheilocystidia 34.2–39.9 × 10.83–14.3 µm, crowded, abundant, utriform to broadly utriform, rarely clavate with an obtuse apex. Paracystidia 13.7–27.9 × 11.4–14.2 µm, subglobose to clavate, hyaline. Caulocystidia 31.1–46.2 × 8.55–12 µm, rarely, various, clavate, utriform, rarely bifurcate. Hymenophoral trama irregular, hyphae inflated up to 18 µm broad. Pileipellis 2–3 layered epithelium, composed of globose to subglobose cells, 20–34.2 µm broad, thin-walled, hyaline. Velar squamules consist of thin-walled, hyaline, branched, 8.5–16.5 µm broad hyphae. Clamps present.
Habit and habitat – Solitary to scattered on dead logs or on decomposed humus of leaf litter in mixed forests.
Distribution – Previously reported from China (Yan and Bau 2018) and Korea (Yoo et al. 2022) as Psathyrella subsingeri T. Bau & J.Q. Yan. This is the first report of C. subsingeri from India.
Material examined – INDIA, West Bengal, Kalimpong District, Lava, Kuwapani, 27°05’00″N 88°37’58″E, elevation 1993 m, 30 May 2023, J. Tamang F-2/2023 (CUH AM979).
GenBank – CUH AM979: PQ152960 (ITS).
Notes – Candolleomyces subsingeri is distinguished by paraboloid to conical pileus, basidiospores 5.98–8.6 × 4.8–5.7 µm, without germ pore, very pale, subhyaline aline to hyaline in 5% KOH and utriform to broadly utriform, rarely clavate with obtuse apex cheilocystidia. This taxon was first reported from Jilin Province, China (Yan and Bau 2018) and later, it was also reported from Korea (Yoo et al. 2022). This is the first record of C. subsingeri from India. The morphological identification of C. subsingeri is well supported by the phylogenetic analyses (Fig. 3). Phylogenetic analyses reveal that our sequence cluster together with the type specimen (NR_160505) reported from China and other deposited sequences of C. subsingeri with well supported bootstrap values (MLBS = 93%, PP = 0.99) suggests all the sequences to be conspecific. Our Indian collection C. subsingeri nicely matches with the description of the type specimen in morphology but slightly differs in size (26–37 µm) and shape of caulocystidia (Yan and Bau 2018). Morphologically, it is also similar to C. luteopallidus (A.H. Sm.) D. Wächt. & A. Melzer but differs in having basidiospore size longer than 8 µm (Yan and Bau 2018; Yoo et al. 2022).
Figure 1 – Basidiomata of Candolleomyces subsingeri. a, b Basidiomata in the field. Scale bars: a, b = 5 cm.
Figure 2 – Microscopic features of Candolleomyces subsingeri (CUH AM979). a Basidiospores. b Basidia. c Pileipellis. d Cheilocystidia. e Caulocystidia. Scale bars: a–e = 5 µm.
Figure 3 – Maximum Likelihood (ML) phylogram (-InL = 11,172.247881) of Candolleomyces inferred from nrITS sequences. Maximum Likelihood bootstrap support values (MLBS) = 50% and Bayesian posterior probabilities values = 0.70 are given above the nodes exclusively. All the taxa are represented along with their GenBank accession numbers and respective country of origin. The tree is rooted with H. leucosticta and H. floriformis. The newly generated sequences from India are kept in bold font.