Clitocybula fuscostriata Q.Na & Y.P.Ge, 2024

Na, Qin, Zeng, Hui, Hu, Yaping, Ding, Hui, Ke, Binrong, Zeng, Zhiheng, Liu, Changjing, Cheng, Xianhao & Ge, Yupeng, 2024, Morphological and phylogenetic analyses reveal five new species of Porotheleaceae (Agaricales, Basidiomycota) from China, MycoKeys 105, pp. 49-95 : 49

Clitocybula fuscostriata Q.Na & Y.P.Ge sp. nov.

Figs 2 , 3 , 4

Diagnosis.

Pileus with dark-brown striae. Differs from C. striata in having broader basidiospores and lacking hymenial cystidia.

Holotype.

China. Zhejiang Province: Baiyun National Forest Park, Liandu District, Lishui City, 2 Aug 2021, Qin Na, Yupeng Ge, Zewei Liu, Yaping Hu, Changjing Liu and Hui Ding, FFAAS1030 (collection number MY0460).

Etymology.

Name refers to the pileus with radially fuscous striae.

Description.

Pileus 3.0-28.5 mm in diameter, hemispherical at first, then convex with depressed centre, expanded with age, infundibuliform with deeply umbilicate at the centre when old, thin-fleshed, dry, surface innately radially Fuscous (XLVI13′′′′k) to Fuscous-Black (XLVI13′′′′m) striate, surface somewhat fibrillose, becoming glabrous, radially cracked at margin when old, Benzo Brown (XLVI13′′′′i), Hair Brown (XLVI17′′′′i), Fuscous (XLVI13′′′′k) to Fuscous-Black (XLVI13′′′′m) at the centre, Pale Smoke Grey (XLVI21′′′′f) in the margin when young, Pale Smoke Grey (XLVI21′′′′f) to Smoke Grey (XLVI21′′′′d) with Bone Brown (XL13′′′m) at the centre when old. Context thin, white, fragile. Lamellae subdecurrent, white, with 1-3 tiers of lamellulae, irregularly intervenose, edges concolorous with the face. Stipe 17.0-52.0 × 1.0-2.5 mm, hollow, cylindrical, strongly and coarsely grooved, slightly bulbous at the base, fragile, finely whitish fibrillose, white in the upper part, Citrine Drab (XL21′′′i) in the base, base covered with a few white fibrils. Odour and taste inconspicuous.

Basidiospores (80/4/3) (5.2) 5.4-5.8-6.2 (6.5) × (4.2) 4.3-4.7-5.0 (5.1) μm [Q = 1.13-1.34, Q = 1.25 ± 0.050] [holotype (40/2/1) (5.3) 5.5-5.8-6.2 (6.5) × (4.2) 4.4-4.6-5.0 (5.1) μm, Q = 1.17-1.32, Q = 1.26 ± 0.040], broadly ellipsoid, hyaline in 5% KOH, smooth, thin-walled, guttulate, amyloid. Basidia 22-32 × 5-9 μm, 2- or 4-spored, clavate, sterigmata 2.5-4.7 × 0.6-1.6 μm. Hymenial cystidia absent. Lamellae edge cells scattered, cylindrical, narrowly clavate, thin-walled. Lamellar trama subregular; hyphae 3-7 μm wide, thin-walled, hyaline, non-dextrinoid. Pileipellis hyphae 4-9 μm wide, smooth; pileocystidia 70-162 × 7-19 μm, cylindrical or narrowly clavate, apically obtuse, thin-walled, hyaline, smooth. Stipitipellis a cutis made up of 3-8 μm wide hyphae, smooth, thin-walled; caulocystidia 27-63 × 5-8 μm, cylindrical, clavate, fusoid, apically obtuse, thin-walled base, smooth, transparent. Clamps present in all tissues.

Habit and habitat.

Scattered on rotten branches or twigs in Acer , Armeniaca , Cercidiphyllum , Emmenopterys and Picea mixed forests.

Known distribution.

Zhejiang Province, China.

Additional material examined.

China. Zhejiang Province: Baiyun National Forest Park, Liandu District , Lishui City , 2 Aug 2021, Qin Na, Yupeng Ge, Hui Zeng and Yulan Sun, FFAAS1029 (collection number MY0459) ; Zhejiang Province: Baiyun National Forest Park, Liandu District , Lishui City , 2 Aug 2021, Qin Na, Yupeng Ge, Zewei Liu, Yaping Hu, Changjing Liu and Hui Ding, FFAAS1031 (collection number MY0466) .

Notes.

Clitocybula fuscostriata is considered to be a distinct species in the genus on account of its pileus with dark-brown striae, broadly ellipsoid basidiospores, absence of cheilocystidia and pleurocystidia and thin-walled pileipellis and stipitipellis hyphae. Five recorded species morphologically resemble this new species: C. familia (Peck) Singer, C. lacerata (Scop.) Métrod, C. oculata (Murrill) H.E. Bigelow, C. striata Dähncke, Contu & Vizzini and C. tilieti (Singer) Singer ( Singer 1943; Romagnesi 1968; Bigelow 1973; Lennox 1979; Ludwig 2000, 2001; Dähncke et al. 2010; Antonín et al. 2011). Clitocybula striata , a new taxon reported from Spain, has certain morphological similarities to C. fuscostriata , namely, a grey-brown to brown pileus with dark-brown striae, but differs from C. striata in having ellipsoid basidiospores (5-7 × 3.5-4.8 μm; Q = 1.5) and presence of utriform or lageniform cheilocystidia ( Dähncke et al. 2010). In contrast to C. fuscostriata , C. tilieti can be easily mistaken for C. striata , but the pileus of C. tilieti is distinctly viscid and its stipitipellis and caulocystidia are thick-walled ( Singer 1943; Antonín et al. 2011). Clitocybula lacerata (Scop.) Métrod, the type species of Clitocybula , is characterised by its caespitose stipes, beige-grey to pale-grey brown pileus, presence of clavate cheilocystidia and a pileipellis with pale encrusting pigmentation, differentiating it from C. fuscostriata ( Peck 1878; Breitenbach and Kranzlin 1991; Ludwig 2000, 2001; Antonín et al. 2019). Clitocybula oculata (Murrill) H.E. Bigelow and C. familia resemble C. fuscostriata in colour and size of the pileus and stipe, but can be distinguished from the new species by the size and shape of the basidiospores [ C. oculata basidiospores (8.5-)10-12(-13) × 6-9 μm, broadly ellipsoid or ovate; C. familia basidiospores 3.5-5.3(-5.5) × 3.5-5.0 μm, globose, subglobose to broadly ellipsoid] ( Romagnesi 1968; Bigelow 1973; Lennox 1979; Ludwig 2000, 2001; Antonín et al. 2011).

Figures

Figure 2. Basidiomata of Clitocybula fuscostriata A-D collection FFAAS 1029 E-F collection FFAAS 1030, holotype G-H collection FFAAS 1031. Scale bars: 10 mm (A-H).

Figure 3. Morphological features of Clitocybula fuscostriata (FFAAS 1030, holotype) A basidiomata B basidiospores C basidia D caulocystidia E pileipellis and pileocystidia. Scale bars: 10 mm (A); 5 μm (B); 10 μm (C-E).

Figure 4. Microscopic features of Clitocybula fuscostriata (FFAAS 1030, holotype) A-E basidiospores F basidia G margin of lamellae H lamellar trama I pileipellis and pileocystidia J caulocystidia. Scale bars: 5 μm (A-E); 10 μm (F-J). Structures were stained with 1 % Congo Red aqueous solution before photographing.