Pholiota cylindrospora E. J. Tian, 2024

Huang, Jia-hui, Lei, Chun-yu, Shen, Ya-lun & Tian, En-jing, 2024, Two new species of Pholiota (Agaricales, Strophariaceae) from the southwest of China, MycoKeys 109, pp. 171-185 : 171-185

Pholiota cylindrospora E. J. Tian sp. nov.

Figs 2 , 3

Diagnosis.

Differs from other Pholiota species by dry pileus with slightly recurved and triangular scales, cylindrical basidiospores, and two types of pleurocystidia, including leptocystidia and chrysocystidia, as well as growing on soil.

Holotype.

China. • Yunnan, Baoshan City, Gaoligong Mountains, Baihualing ; elev. 910 m; 25 ° 03 ' 33 ′′ N, 98 ° 49 ' 18 ′′ E; scattered on soil in broad-leaved forest; 30 November 2015; Shi-liang Liu 37432 (holotype: HMJAU!).

Etymology.

Referring to the cylindric basidiospores.

Description.

Pileus 50–70 mm in diameter, convex to broadly convex, becoming nearly plane, with a low obtuse umbo; surface dry, pale orange to apricot (5 A 3–5 B 6), paler towards the margin, decorated with concentric, slightly recurved, triangular, light brown (6 D 7) scales. Context pale (2 A 2), odor and taste mild. Lamellae adnate, broad, moderately close, L = 38–42, I = 2–6, pallid at first, becoming brown (6 D 6), the edges waved. Stipe 45–60 mm long, 8–11 mm thick, central, equal to tapered towards the base, solid, ground color pallid, smooth to silky above an annular zone, towards the base with yellowish brown to brown (5 D 6–6 D 6) multizonate squamules or sometimes with scattered brown (6 D 5) fibrils, with white mycelium at the base.

Basidiospores (6.5 –) 7.0–9.5 (– 10.0) × 3.0–4.0 µm, Q = 1.75–2.83, Q m = 2.30, in face view oblong to cylindric, sometimes crooked, in profile cylindric to slightly inequilateral, wall smooth and thin, germ pore very minute to not evident, pale rusty to yellowish brown (6 E 8–5 E 8) in KOH, slightly paler in Melzer’s reagent. Basidia 19–27 × 4.9–6.5 µm, 4 - spored, clavate, hyaline in KOH. Pleurocystidia of two types: 1) leptocystidia, 35–55 × 8.5–10 µm, clavate to subfusoid, thin-walled, smooth, content homogeneous, hyaline to pale yellowish brown to brownish (5 D 5–5 E 7) in KOH; 2) chrysocystidia, 39–60 × 9.5–12.5 µm, lageniform to clavate with a rostrate to mucronate apex, rarely forked near the apex, with an amorphous highly refractive inclusion, pale rusty to yellowish brown (6 E 8–5 D 5) in KOH. Cheilocystidia 23–39 × 6–11 µm, fusiform, clavate to subcapitate at apex, wall thin and smooth, content homogeneous, hyaline, pale yellow to yellow brownish (4 A 3–5 C 7) in KOH. Caulocystidia not observed. Gill trama of parallel hyaline to yellowish white (4 A 2) hyphae in KOH and with smooth walls, the cells inflated, up to 23 µm in diam. Pileipellis a cutis of brownish yellow to light brown (5 C 8–5 D 5) hyphae 4.5–11 µm in diam., thin-walled, slightly incrusted to asperulate. Clamp connections present in all the tissues.

Habitat.

Scattered on soil in broad-leaved forest in late autumn.

Additional materials examined.

China. • Yunnan: Tengchong City, Yunfeng Mountain , on soil; 15 November 2019; Xiao-ming Zhang 37433 ( HMJAU) .

Discussion.

Cylindrical basidiospores are uncommon in the genus Pholiota , making this species easily distinguishable from the others. In addition, it is readily recognized because of its dry pileus with slightly recurved and triangular scales and two types of pleurocystidia, including leptocystidia and chrysocystidia, as well as its growth on soil.

The stipe with multizonate squamules of this species reminds one of Pholiota multicingulata Horak , but the latter has smaller basidiospores (6.5–8 × 4.5–5 µm) and lacks chrysocystidia ( Horak 1983).

Pholiota cylindrospora is similar to P. squarrosa (Vahl) P. Kumm. Both species have a dry pileus with obvious scales and two types of pleurocystidia: leptocystidia and chrysocystidia. However, the latter has smaller (6–7.5 × 3.8–4.5 µm) and elliptic basidiospores with a distinct germ pore and is wood-inhabiting ( Smith and Hesler 1968; Holec 2001). P. kodiakensis A. H. Sm. & Hesler with two types pleurocystidia is also similar to P. cylindrospora ; however, the former can be distinguished from the latter by its shorter spores (5–6 × 3–3.5 µm) and distinct germ pores with truncate apex ( Smith and Hesler 1968). Furthermore, in the phylogram, P. cylindrospora clustered in the Subgenus Pholiota clade (Fig. 1 ). In this clade, this species was sister to P. kodiakensis and P. squarrosa with high statistical support (PP = 1, BS = 100), but represented a relatively independent lineage (Fig. 1 ). Therefore, it is proposed here as a new species belonging to Pholiota subgenus Pholiota based on morphological examination and phylogenetic analyses.

Figures

Figure 1. BI phylogram of Pholiota based on the dataset (ITS + 28 S). PPs > 0.95 and bootstrap values > 70 % are shown. Types are indicated in green, and the new species from China in this study are in red.

Figure 2. Basidiomata of Pholiota cylindrospora (HMJAU 37432, holotype). Photo by Shi-liang Liu. Scale bar: 1 cm.

Figure 3. Microcharacters of Pholiota cylindrospora (HMJAU 37432, holotype). Drawings by Jia-hui Huang A basidiocarps B basidia C basidiospores D pleurocystidia E cheilocystidia. Scale bars: 1 cm (A); 5 µm (C); 10 µm (B, D, E).