Grammothele taiwanensis C.C. Chen, sp. nov.
Index Fungorum number: IF 900073; MycoBank number: MB 900073; Facesoffungi number: FoF 13396; Fig. 1
Etymology – Referring to the type locality, Taiwan.
Holotype – GC 1704-17
Basidiomata annual, resupinate, effused, adnate, corky when dry, up to 15 cm long, 6 cm wide, and 1.3 mm thick in section, sparsely cracked, growing beneath the bark; margin sterile, cottony or slightly fimbriate, sometimes indistinct. Pore surface cream, buff-yellow or buff upon drying, not changing in KOH; pores angular, 3–5 per mm; dissepiments thin, entire, sometimes lacerate. Tubes concolorous with pore surface, corky, up to 1 mm deep. Context cream, corky, up to 0.3 mm thick, or sometimes invisible. Hyphal system dimitic in both context and trama; generative hyphae nodose-septate; tissues not changing in KOH. Context generative hyphae colorless, unbranched, 2.5–3.5 µm diam, thin-walled; skeletal hyphae, colorless, slightly flexuous, occasionally branched, 2.5–3.5 µm diam, thick-walled with a wide lumen or almost solid, weekly dextrinoid. Tramal generative hyphae colorless, flexuous, frequently branched, 2–3.5 µm diam, thin-walled; skeletal hyphae colorless, slightly flexuous, rarely branched, 3–4.5 µm diam, thick-walled with a wide lumen or subsolid, often agglutinated in bundles, weekly dextrinoid. Cystidia absent. Cystidioles fusoid, colorless, thin-walled, 14–20×4.5–5 µm. Dendrohyphidia colorless, thin-walled, 9–23 × 1.5–2.5 µm. Hyphidia colorless, thin-walled, 19–26 × 2–3 µm. Basidia clavate or suburniform, with four sterigmata and a basal clamp connection, colorless, thin-walled, 17–25 × 6–7 µm. Basidiospores cylindrical, colorless, thin-walled, smooth, inamyloid, nondextrinoid, acyanophilous, mostly 7.9–10.5 × 3.3–4.4 µm. (7.8–)8 .4–10.5(–12.3) × (3.5–)3.7–4.4(–5.1) µm, L = 9.4 µm, W =4.1 µm, Q =2.23–2.43 (n=30) (holotype). (7–)7.9–9 .4(–10.6)×(3–)3.3–3.9(–4.3) µm, L=8.6 µm, W=3.6 µm, Q =2.3–2.45 (n=30) (GC 1704–16).
Material examined – China: Taiwan, Nantou County, Yuchih Township, Shuishetashan Trail, 23° 51′ N, 120° 56′ E, 980 m, on angiosperm branch, 8 April 2017, GC 1704–17 (TNM F31469, holotype).
GenBank number – MW440487 (ITS).
Additional specimen examined – China: Taiwan, Nantou County, Yuchih Township, Shuishetashan Trail, 23° 51′ N, 120° 56′ E, 980 m, on angiosperm branch, 8 April 2017, GC 1704–16 (TNM F31468).
GenBank number – MW440486 (ITS).
Notes – Grammothele taiwanensis is characterized by having resupinate, cream to buff basidiomata with larger pores (3–5 per mm), dimitic hyphal system with clamped generative hyphae and weekly dextrinoid skeletal hyphae, presence of fusoid cystidioles, dendrohyphidia and hyphidia, and cylindrical basidiospores (7.9–10.5×3.3–4.4 µm). Grammothele taiwanensis resembles G. pulchella (Bres.) Ryvarden in having similar pore and basidiospore sizes [4–5 per mm, 7–10 × 3–4 µm in Hjortstam and Ryvarden (1982), as G. ochracea Ryvarden] and presence of dendrohyphidia; however, G. pulchella differs from this species in having cork-colored to woodcolored pore surface and pale brown context, and absence of cystidioles and hyphidia (Hjortstam and Ryvarden 1982). Grammothele taiwanensis is also similar to G. hainanensis F. Wu & L.W. Zhou and G. hondurensis (Murrill) Ryvarden, but the latter two species have hyphal pegs and smaller basidiospores [G. hainanensis: 7–8.1×2.3–2.9 µm in Wu et al. (2016); G. hondurensis: 5–8 × 3–3.5 µm in Ryvarden (1985)]. Phylogenetically, two sequences of G. taiwanensis formed an isolated lineage with high support (Fig. 2).
Figure 1 – Grammothele taiwanensis (GC 1704–17, holotype). a, b Basidiomata. c Generative hyphae from trama. d Skeletal hyphae from trama. e Generative hyphae from context. f Skeletal hyphae from context. g Dendrohyphidia. h Hyphidia. i Cystidioles. j Basidia. k Basidiospores. Scale bars: a–b=1 cm, b–j=10 μm, k=5 μm
Figure 2 – Phylogram generated from maximum likelihood analysis based on ITS sequence data of Grammothele taiwanensis (in bold) and related species. The selection of strains and species consulted Zhou and Dai (2012), Yuan (2015), Wu et al. (2016) and Hyde et al. (2019). Funalia trogii is used as the outgroup taxa. Forty-six strains are included in the sequence analyses, which comprise 665 characters with gaps. The tree topology of the ML analysis was similar to the BI. The best scoring RAxML tree with a final likelihood value of is presented. Bootstrap support values for ML≥70%, BYPP≥0.9 are given above the nodes