Laccaria rubroalba

Laccaria rubroalba X. Luo, L. Ye, P.E. Mortimer & K.D. Hyde

Index Fungorum number: IF552302; Facesoffungi number: FoF 02078

Basidiomata medium size. Pileus 22–40 mm in diam., less than 1 mm thick at disc., hemispherical to convex, flattened with age, centrally depressed to umbilicate, smooth with translucent-striate ridges, reddish-white (10A2) when moist or young, becoming white to paler when dry. Context soft. Lamellae up to 4 mm broad, distant, adnate, ventricose to broadly ventricose, flesh-coloured. Stipe 20–31 × 2–4 mm, cylindrical with an enlarged base, centrally inserted, fistulose, fleshy brown, becoming pale brownish with age, and with rhizomorphs.

Basidiospores (5) 6–9 (10) × 5–7 (8) μm, Q = 0.97–1.31, globose, to subglobose to broadly ellipsoid, hyaline, moderately echinulate, 1.2–2.7 μm long, 0.73–0.96 μm broad at the base. Basidia 28–56 × 9–10 (11) μm, 4-spored, some 2-spored, hyaline. Pleurocystidia (20) 25–40 (55) × 4–6 (7) μm, flexuous to narrowly-cylindrical. Cheilocystidia rare, (11) 12–26 (26) × 5–9 μm, cylindrical to capitate; margin cell 18–33 × 3–6 μm, cylindric to clavate. Pileipellis a cutis to interwoven, 4–9 (13) μm diam thickness, consisting of radiating interwoven hyphae, with rounded top and thick-walls (up to 1.20 μm). Hyphae 3–6 μm diam, Clamp connections present. (Figs. 1–2)

Etymology: The species epithet “rubroalba” refers to the pileus colour of the new species.

Habitat and Distribution: Scattered on a trunk of Castanopsis mekongensis in a tropical forest dominated by mixed Fagaceae and broad-leaf trees in Xishuangbanna, Yunnan, China.

Material examined: CHINA. Yunnan Province: Xishuangbanna, Mengsong village, elevation 1734 m, N21° 30’ 52”, E100° 28’ 44.76”, 18 August 2013, Xia Luo (KUN-HKA 90753, Holotype). CHINA. Yunnan Province: Xishuangbanna, Mengsong village, elevation 1694 m, N21° 30’ 53”, E100° 28’ 49.1”, 5 September 2012, Xia Luo (KUN-HKA 90758, Paratype). CHINA. Yunnan Province: Xishuangbanna, Mengsong village, elevation 1635 m, N21° 30’ 14.4”, E100° 29’ 22.5”, 12 October 2012, Xia Luo (KUN-HKA 90766, Paratype). CHINA. Yunnan Province: Xishuangbanna, Mengsong village, elevation 1635 m, N21° 30’ 14.4”, E100° 29’ 22.5”, 20 September 2012, Xia Luo (KUN-HKA F90751, Paratype).