Xeromphalina brevipes T. Bau & L N. Liu, 2018

Liu, Li-Na & Bau, Tolgor, 2018, Two new Xeromphalina (Mycenaceae, Agaricales) species with eccentric stipes from subtropical China, Phytotaxa 379 (4), pp. 277-286 : 280-281

Xeromphalina brevipes T. Bau & L N. Liu sp. nov. ( Figure 2 , 3 )

Mycobank No. MB828077

Diagnosis:—Pileus convex to plano-convex, pale yellow to pale yellow-brown, paler towards striate margin, decurrent lamellae, yellow, short, eccentric or lateral stipe, basidiospores cylindrical, basidia 4-spored, cheilocystidia fusoid or lageniform, pleurocystidia absent, pileipellis turns orange-brown in KOH, subpileipellis turns pale brownish yellow to brown in KOH, circumcystidia coralloid, caulocystidia coralloid.

Etymology:—referring to the short stipe

Type:— CHINA. Anhui Province, Huangshan city, Huangshan Scenic Spot, 30°07′49″ N, 118°10′18″ E, 3 July 2018, Tolgor Bau and Lina Liu, Voucher : HMJAU47744 (Holotype!)

Description:— Pileus 1–6 mm in diam., hemispherical to convex when young, expanding to plano-convex without depressed centre when old, hygrophanous, translucent-striate at margin, yellow-brown (5C7) at centre, pale yellow (5A3) to yellow-brown (5B3) towards striate margin, glabrous, darker and becoming rugose when dry. Lamellae decurrent with few lamellulae (L=15–24, I=1–2), moderately crowded, sometimes anastomosed, narrow, grey-yellow (4A2) to yellow (4A4), margins even. Stipe 2–5 × 0.5–1.2 mm, eccentric or lateral, almost cylindrical, yellow-brown (5C7), entirely pubescent, with slightly darker yellow-brown (5D7) basal tomentum. Context pale yellow (4A2). Smell and Taste indistinct. Rhizomorphs absent.

Basidiospores 4.9–5.8 × 1.9–2.1 μm, Q = 2.0–2.7, amyloid, cylindrical, hyaline, thin-walled, smooth. Basidia 10–18 × 3–5 μm, 4-spored, narrowly clavate to subcylindrical. Lamellar edge heterogeneous, composed of scattered cheilocystidia mixed with basidia and basidioles. Cheilocystidia 17–27 × 3–7 μm, fusoid or lageniform, thin-walled, hyaline. Pleurocystidia absent. Pileitrama made up of cylindrical, sometimes inflated thin- to slightly thick-walled, 3– 8 μm wide hyphae, smooth or encrusted with brownish pigment which turns orange-brown in KOH. Pileipellis a cutis, made of parallel, cylindrical, slightly thick-walled, 2–9 μm wide hyphae, sometimes incrusted, with yellowish brown parietal pigment which turns orange-brown in KOH. Subpileipellis made up of parallel, 2–6 μm wide hyphae, with slightly encrusting yellowish brown pigment, which turns pale yellowish brown to brown in KOH. Circumcystidia abundant, 17–39 × 3–5 μm, cylindrical, with lateral projections or coralloid, thick-walled, orange-yellow-brown in KOH. Stipitipellis a cutis of parallel, cylindrical, thick-walled hyphae, with pale yellow or brown parietal pigment which turns brown or light brownish yellow in KOH. Caulocystidia 24–49 × 4–12 μm, clavate, cylindrical or utriform, sometimes with apical capitulum or one branch, irregular to subcoralloid, thick-walled, orange-brown or light brownish yellow in KOH. Clamp-connections present in all tissues.

Habitat: Saprophytic; scattered or gregarious on decaying wood covered with mosses.

Known distribution: Anhui Province, China

Additional material examined: CHINA. Anhui Province, Huangshan city, Huangshan Scenic Spot, 30°07′49″ N, 118°10′18″ E, 4 July 2018, Tolgor Bau and Lina Liu, Voucher : HMJAU47746.

Figures

FIGURE 2. Basidiomata of Xeromphalina brevipes. Scale bar=5 mm; a. HMJAU47746; b. HMJAU47744. Photos by: Lina Liu

FIGURE 3. Features of Xeromphalina brevipes. a. Basidiomata; b. Basidia; c. Basidiospores; d. Cheilocystidia; e. Elements of pileipellis; f. Elements of stipitipellis. Scale bars a=5 mm; c=5 μm; b, d, e, f =10 μm. All drawings from holotype. Drawings by: Lina Liu.