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.

Figure 2. 

Basidiomata of Pholiota cylindrospora (HMJAU37432, holotype). Photo by Shi-liang Liu. Scale bar: 1 cm.

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!).

Figure 3. 

Microcharacters of Pholiota cylindrospora (HMJAU37432, 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).

Referring to the cylindric basidiospores.

Pileus 50–70 mm in diameter, convex to broadly convex, becoming nearly plane, with a low obtuse umbo; surface dry, pale orange to apricot (5A3–5B6), paler towards the margin, decorated with concentric, slightly recurved, triangular, light brown (6D7) scales. Context pale (2A2), odor and taste mild. Lamellae adnate, broad, moderately close, L = 38–42, I = 2–6, pallid at first, becoming brown (6D6), 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 (5D6–6D6) multizonate squamules or sometimes with scattered brown (6D5) 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 (6E8–5E8) 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 (5D5–5E7) 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 (6E8–5D5) 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 (4A3–5C7) in KOH. Caulocystidia not observed. Gill trama of parallel hyaline to yellowish white (4A2) 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 (5C8–5D5) hyphae 4.5–11 µm in diam., thin-walled, slightly incrusted to asperulate. Clamp connections present in all the tissues.

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

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

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.

Pholiota subterrestris is distinguished from the other species of the genus Pholiota by brownish orange pileus with numerous brown fibrillose scales, pale brown and moderately broad lamellae with even edges, stipe covered with recurved fibrillose scales, evanescent fibrillose annulus; elliptic spores with distinct but small germ pore, fusoid ventricose pleurocystidia with typical amorphous refractive inclusion of chrysocystidia.

Figure 4. 

Basidiomata of Pholiota subterrestris (HMJAU37434, holotype). Photo by En-jing Tian. Scale bar: 1 cm.

China. • Guizhou: Bijie City, Nayong County, Dapingqing National Wetland Park; elev. 1990 m; 26°41'10′′N, 105°27'30′′E; scattered on soil at base of stump; 22 July 2020; En-jing Tian 37434 (holotype: HMJAU!).

Figure 5. 

Microcharacters of Pholiota subterrestris (HMJAU37434, holotype). Drawings by Jia-hui Huang A basidiocarps B basidia C basidiospores D pleurocystidia E cheilocystidia F pileipellis. Scale bars: 1 cm (A); 5 µm (C); 10 µm (B, D, E); 20 µm (F).

The epithet subterrestris refers to the similarity to Pholiota terrestris.

Pileus 10–35 mm in diameter, subhemispherical when young, with involute margin, slightly spread when mature, surface slightly viscid when wet, greyish orange to brownish orange (5B4–6C6), center dark, becoming paler towards the margin, covered with brown (6E7) fibrillose scales. Context thick, white to yellowish white (1A1–2A2), mild odor and taste. Lamellae decurrent to adnate or adnexed, moderately broad, close, L = 39–44, I = 3–7, pale yellow to light brown (4A3–5D6), edges even. Stipe 18–30 mm long, 4–7 mm thick, central, equal, solid, brownish orange (5C4) above, brown (6E5) below, covered with light brown (6D6) fibrillose squamulose, often compressed at the base

Basidiospores 5.4–6.1 × 3.6–4.2 µm, Q = 1.30–1.56, Q_m = 1.47, smooth, in face view broadly elliptic to elliptic, in profile a little bean-shaped, apical pore distinct but small, containing oil-bearing droplet or irregular inclusions, greyish yellow (4B5) in KOH and light yellow (4A5) in Melzer’s reagent. Basidia 17.1–21.8 (–24.0) × 5.0–6.3 µm, 4-spored, clavate, hyaline in KOH, pale yellow (4A3) in Melzer’s reagent. Pleurocystidia of two types: 1) 33.3–46.7 × 5.5–9.5 µm, subclavate to fusoid ventricose with a subacute apex, wall thin and smooth, content homogeneous, blond to dark yellow (4C4–4C8) to hyaline in KOH; 2) chrysocystidia, 34.2–58 × 8.3–10.4 µm, fusoid to fusoid-ventricose, the neck often drawn out to a crooked filamentose projection with a subacute apex (up to 19.6 µm long), walls thin, smooth, with a refractive-amorphous inclusion, hyaline in KOH. Cheilocystidia abundant, (20.0–) 22.9–39.2 (–48.3) × 3.9–12.7 µm, clavate to clavate-capitate, wall thin, at times somewhat thickened in apex (about 1 µm), hyaline in KOH. Caulocystidia none observed. Gill trama of parallel hyphae, the cells inflated up to 27.5 µm, thin-walled, smooth, hyaline in KOH. Pileipellis hyphae hyaline to light brown (6D7), 3.7–10 µm diam., with encrusted walls. Content hyphae hyaline, 10–37.5 (–50) µm diam., cells inflated, smooth and thin-walled. Clamp connections present in all the tissues.

Scattered or gregarious on soil at the base of a stump or on buried wood in summer.

China. • Guizhou: Bijie City, Qixingguan District, Baima Mountain, gregarious on soil or on buried wood, 15 August 2022, Guang-cheng Cao 37435 (HMJAU).

This species is characterized by a brownish orange pileus with numerous brown fibrillose scales, pale brown lamellae with even edges, a stipe covered with recurved fibrillose scales, an evanescent fibrillose annulus, elliptic spores with a distinct but small germ pore, and fusoid ventricose pleurocystidia with typical amorphous refractive inclusions of chrysocystidia.

Pholiota subterrestris is similar to P. terrestris Overh., especially in terms of micro-characteristics, such as pleurocystidia, cheilocystidia, and basidiospores. However, it is easy to differentiate between the two species based on the macro characteristics. P. terrestris has a larger pileus (20–80 mm broad) without an orange tone, narrow and crowded lamellae with uneven edges, and a longer stipe (30–80 mm long) (Smith and Hesler 1968). Furthermore, in habitat, P. terrestris is caespitose on soil, whereas P. subterrestris is scattered or gregarious. Phylogenetic analyses showed that P. subterrestris was sister to P. terrestris in the Subgenus Pholiota clade (Fig. 1), which also indicated a close relationship between the two species.