Crepidotus lutescens T. Bau & Y.P. Ge, 2017

Ge, Yupeng, Yang, Sisi & Bau, Tolgor, 2017, Crepidotus lutescens sp. nov. (Inocybaceae, Agaricales), an ochraceous salmon colored species from northeast of China, Phytotaxa 297 (2), pp. 189-196 : 191-192

Crepidotus lutescens T. Bau & Y.P. Ge sp. nov. ( Fig. 1 , a–d)

Fungal Name registration No.: FN570258

Diagnosis:— Crepidotus lutescens is charactered by its yellow to ochraceous pileus, broadly ellipsoid granular-warty basidiospores, and lageniform cheilocystidia with capitates apices. Etymology:— lutescens (Latin) , of a yellowish color. Type:— CHINA. Jilin Province: Erdaobaihe Town, Yanbian Korean Autonomous Prefecture, 753m asl, 44°40′N, 128°09′E, 21 June 2015,

Yupeng Ge, HMJAU37002 (Holotype!) ; same location, 27 June 2009, Tolgor Bau, HMJAU21976 (Isotype!) .

Pileus (17–)28–47(–58) mm in diameter, reniform to more or less ungulate in young stages, antimony yellow (5C6– 5C8) to light ochraceous-salmon (6A7–6B7), with a whitish-translucent (5A1–5B1) edge, not or slightly translucent striate, becoming flabelliform to semicircular or petaloid, ochraceous salmon (6B7–6B8), with light buff (6C7–6D7) striate edge when matured, directly attached laterally to the substratum, hygrophanous tomentose off the edge, with dense white villosity near the point of attachment, with inflexed margin when young, later with slightly straight margin, sometimes pileus honey yellow to maize yellow (5B5–5B7) when matured; the color turns to dark brown in KOH. Lamellae 2.0–3.0(–5.0) mm broad, moderately crowded, light ochraceous-salmon to saffron yellow (6A7–6D7), adnexed to adnate, subventricose; edge even. Stipe 2.0 × 3.5 mm, only visible in very young stage, straight to lightly curved, beige-translucent, pruinose. Context 0.5–1.0 mm thick, white, unchanging on exposure. Odor and taste not distinct. Spore print orange brown.

Basidiospores (5.8–)6.1–6.9(–7.2) × (4.5–)4.9–5.3(–5.9) μm, Q=1.1–1.3, subglobose to broadly ellipsoid, clearly narrower towards the apex, clay brown to nut brown, with a granular-warty ornamentation. Basidia (23.9–)24.7– 30.9(–32.8) × (4.9–)5.1–6.5(–6.8) μm, 2- or 4-spored, thin-walled, hyaline, clamped at the base. Pleurocystidia absent. Cheilocystidia (30.1–)33.6–46.8(–58.3) × (8.8–)9.5–12.1(–13.0) μm, not abundant, lageniform with capitate apex, rarely branched, scattered or occasionally clustered, thin-walled, hyaline, clamped at the base. Pileipellis a loose trichoderm; hyphae interwoven to erect, filiform, hyaline. Pileus trama differentiated into 2 layer, upper one beneath pileipellis, constant in depth hyphae composed of cylindrical cells, 8.1–12.3 × 32–38 μm, taper to one side or both at times, thin-walled, undifferentiated, yellow orange colored; below that is a thin-walled, colorless, gelatinized layer comprising most of the pileus context ( Fig. 2 ).

Habitat:—Gregarious, on decaying wood of Populus and Ulmus , in temperate forests.

Known distribution:— China.

Additional Material examined:— CHINA. Jilin Province: Erdaobaihe Town, Yanbian Korean Autonomous Prefecture , 753m asl, 42°40′N, 128°09′E, June 21 2015, Yu-guang Fan, 8 July 2007, HMJAU7157 ; Tolgor Bau , 26 June 2009, HMJAU22105 ; Tolgor Bau , 8 July 2011, HMJAU27196 ; Tolgor Bau , 23 June 2012, HMJAU27222 ; Yupeng Ge , 4 July 2015 ; HMJAU37003 ; Lushuihe Town, Baishan City , 723m asl, 42°52′N, 127°88′E, Tolgor Bau, 28 June 2005, HMJAU5807 ; Helong City, Yanbian Korean Autonomous Prefecture , Jilin Province, 842m asl, 42°51′N, 129°08′E, Tolgor Bau, 11 July 2010, HMJAU27279 ( HMJAU!) .

Figures

FIGURE 1. Crepidotus lutescens Scale bars=10mm. Photos a–c by Tolgor Bau; d by Yupeng Ge

FIGURE 2. Crepidotus lutescens (HMJAU37002, holotype) a. Basidiocarp b. Pileipellis c. Basidiospores d. Basidia e. Cheilocystidia Bars a=1cm, b=30μm, c= 5μm, d, e=10μm Illustration by Yupeng Ge.