Clitopilus fusiformis D. Wang & Xiao-Lan He, 2017

Wang, Di, Deng, Wang-Qiu, He, Xiao-Lan, Peng, Wei-Hong & Gan, Bing-Cheng, 2017, Clitopilus fusiformis (Entolomataceae; Agaricales), a new species from southwest China, Phytotaxa 321 (2), pp. 201-207 : 202-203

Clitopilus fusiformis D. Wang & Xiao-Lan He , sp. nov. ( Figs. 1 and 2 )

MycoBank no.: MB 819427

Diagnosis:— Clitopilus fusiformis could be mistaken as C. prunulus (Scop.) P. Kumm. based on the pale colored basidiomata, but the latter differs in terms of a more robust stipe and smaller basidiospores.

Etymology:— fusiformis (Lat.) , referring to the shape of the basidiospores.

Type:— CHINA. Yunnan Prov.: Shangri-La, Potatso National Park, elev. ca. 3,400 m, 99°60′22″ E, 27°52′41″ N. September 7, 2015, He XL (holotype, SAAS 1892!).

Sequences ex holotype:—KU751777 (ITS), KY385633 (RPB2).

Macroscopic characteristics:—Basidiomata medium-sized. Pileus 25–45 mm in diam, plano-concave, sometimes irregularly shaped; margin often slightly involuted; surface dry, more or less velvety, pale grayish or gray whitish,

not hygrophanous, not striate. Lamellae short decurrent, dense, whitish at first, later becoming pinkish, up to 3 mm in height; with 2–3 tiers of lamellulae. Stipe 22–40 mm in length, 2.5–3.5 mm in diameter, pale grayish, dry, solid at first then hollow, usually off center, base slightly inflated with cream white cottony mycelium. Odor and taste indistinct.

Microscopic characteristics:—Basidiospores 10.5–14 × 5.0–7.0 μm, L m = 12.0 ± 0.87 × 6.0 ± 0.56 μm, Q = 1.65– 2.3, Q m = 2 ± 0.17, hyaline, thick walled, fusiform with 5–6 longitudinal ridges in profile and face views, angled in polar view. Basidia 21.5–24.0 × 6.5–7.5 μm, clavate, hyaline, 4-spored, sterigmata reaching 2.0–3.0 μm. Lamellar trama interwoven, hymenium hyphae 3–5 μm in diam, hyaline. Pileipellis a trichoderm of some entangled, non-

encrustated, hyaline hyphae; terminal elements cylindric to subclavate (measuring 3.5–5.5 μm in diam). Pleurocystidia and cheilocystidia absent. Stipipellis regular, cylindrical and colorless hyphae 4–6 μm in diam, with some upturned terminal cells. Clamp connections absent in all tissues.

Ecology and distribution:—Scattered, among mosses on the soil in spruce and fir forest; China (Yunnan and

Sichuan).

Additional materials examined:— CHINA. Yunnan Prov.: Shangri-La, Potatso National Park, elev. ca. 3,400 m,

September 7, 2015, He XL (SAAS 1038!). Sichuan Prov.: Yajiang, elev. ca. 3,500 m, September 4, 2015, He XL (SAAS

1587!).

Comments:— Clitopilus fusiformis is characterized by its medium-sized and pale grayish basidiomata, slightly eccentric stipe, fusiform basidiospores with 5–6 longitudinal ridges.

Clitopilus fusiformis is placed in sect. Clitopilus due to its slightly eccentric stipe, fusiform basidiospores with

5–6 longitudinal ridges and 10–14 μm in length. Ten species in sect. Clitopilus have been previously described ( Hongo 1954, Hansen & Knudsen 1992, Noordeloos 1993, Baroni & Halling 2000, Yang 2007, Vizzini et al. 2011, Deng et al. 2012, Morgado & Noordeloos 2012). C. amygdaliformis Zhu L. Yang , known from tropical China, differs notably from C. fusiformis by its white to chalk white pileus, and smaller basidiospores (8.0–11.5 × 6.0–8.0 μm, Yang 2007). C. cystidiatus Hauskn. & Noordel. , described from Austria, differs in its ochre tinged pileus and presence of cheilocystidia ( Vizzini et al. 2011). C. ravus W.Q. Deng & T.H. Li , also found in southwestern China, is separated from C. fusiformis by its tawny gray or grayish brown pileus, amygdaliform, or subfusiform basidiospores with 4–5 longitudinal ridges ( Deng et al. 2012). C. austroprunulus Morgado, G.M. Gates & Noordel. , discovered in a broadleaf forest in Australia, is distinguished by its significantly smaller basidiospores that measured (8–)9–11 × 4.5–6 μm ( Morgado & Noordeloos 2012). C. prunulus is differed by its more robust stipe and smaller basidiospores measuring 10.5–12.5 × 5–6.5 μm ( Noordeloos 1993). C. griseobrunneus T.J. Baroni & Halling , described from Costa Rica, was found in a tropical montane oaks forest and distinguished by its brown to grayish brown pileus and dark brown incrusted pigment in the pileipellis ( Baroni & Halling 2000). C. lignyotus Hongo , originally described from Japan, differs from C. fusiformis by its grayish brown to blackish brown pileus and narrower basidiospores measuring 9.5–13 × 4.5–6 μm ( Hongo 1954). C. paxilloides Noordel. is readily separated by its gray-brown spots on the pileus surface, a gray-brown to grayish stipe, and strongly encrusted pigment in the pileipellis ( Noordeloos 1993). C. chrischonensis Musumeici, Vizzini & Contu differs by the presence of cheilo and pleurocystidia ( Vizzini et al. 2011). C. quisquiliaris (P. Karst.) Noordel. is easily distinguished by its reddish brown pileus ( Hansen & Knudsen 1992).

Figures

FIGURE 1. Basidiomata of Clitopilus fusiformis (photographed by He Xiao-Lan).

FIGURE 2. Microstructures of Clitopilus fusiformis (holotype). a. Basidiospores. b. Basidia. c. Pileipellis.