Melanoleuca pallidorosea X.D. Yu & H.B. Guo, 2021

Pei, Ying, Guo, Hong-Bo, Liu, Tie-Zhi, Qin, Wei-Qiang, Zhao, Di, Qi, Xiao-Jian & Yu, Xiao-Dan, 2021, Three new Melanoleuca species (Agaricales, Basidiomycota) from north-eastern China, supported by morphological and molecular data, MycoKeys 80, pp. 133-148 : 133

Melanoleuca pallidorosea X.D. Yu & H.B. Guo sp. nov. Figs 5 , 6h, i

Etymology.

The epithet refers to the species which has a pallid rose pileus.

Diagnosis.

The new species is distinguished from M. grammopodia and M. leucopoda in having a pinkish-white pileus.

Type.

China. Inner Mongolia: Xilingole League, Xiwuzhumuqin Banner , on the grass in woods, 1051 m alt., 44.48°N, 117.86°E, 22 Aug 2017, X.D. Yu (holotype: SYAU-FUNGI-058) .

Description.

Pileus 30-65 mm diam., flat, with depressed centre, margin slightly undulating, expanding to uplifted, sometimes slightly lacerate when mature, surface glabrous, camel (9E8 to 10E8) at centre, pinkish-white (10A3 to 10A4) towards the margin. Lamellae rather distant, adnate to decurrent, white, 3.0-4.5 mm broad, with lamellulae of two lengths, but not intervening, edge entire. Stipe cylindrical, 20-50 mm long × 5-8 mm diam., in upper part of stipe apricot (6C8 to 6D8), becoming yellowish-brown (5E8) towards base, with whitish flocculose apex, longitudinally striate, with whitish basal tomentum. Context up to 2-5 mm thick at the pileus base, whitish to creamy, whitish in stipe cortex and base. Smell fungoid smell, taste mild. Spore print white.

Basidiospores (130/7/4) (6.5) 7.0-8.5 (9.0) × 5.0-6.0 (6.5) μm, av. 7.4 × 5.5 μm, Q = (1.28)1.31-1.40(1.44), ellipsoid, hyaline, ornamentation verruculose, warts mainly round and scattered, amyloid. Basidia (20) 25-33 (35) × (6.0) 6.5-9.5 (10.5) μm, av. 28 × 8.5 μm, clavate, 4-spored, occasionally 2-spored, subhyaline. Hymenial cystidia absent. Lamella edge sterile. Hymenophoral trama 95-159 μm wide, regular, with thin-walled hyphae, 5.0-10.0 μm diam., hyphae not pigmented. Subhymenium poorly developed. Pileipellis a cutis of numerous repent branched hyphae, 4.0-10.0 μm wide, inflated cell to 21.0 μm, thin-walled. Stipitipellis hyphae 7.0-10.0 μm, thin-walled, hyaline. Caulocystidia absent. Clamp connections absent.

Habit, ecology and distribution.

Solitary or in small group, saprotrophic in grass. Known from north-eastern China.

Additional specimens examined.

China. Inner Mongolia: Xilingole League, Xiwuzhumuqin Banner , on the grass in woods, 1051 m alt., 44.48°N, 117.86°E, 22 Aug 2017, X.D. Yu (SYAU-FUNGI-065). Chifeng City , Bahrain Banner Saihanwula , 10 Sep 2016, T.Z. Liu & Z.L. Song (CFSZ 12136); 12 Sep 2016, T.Z. Liu & Z.L. Song (CFSZ 12253) .

Figures

Figure 5. Melanoleuca pallidorosea (holotype, SYAU-FUNGI- 058) A macroscopic habit B surface of basidiospores. Scale bars: 1 cm (A); 2 μm (B).

Figure 6. Line drawings of the three new Melanoleuca species A-C Melanoleuca chifengense (holotype, SYAU-FUNGI- 059) A basidiospores B, C basidia and basidioles D-G Melanoleuca griseoflava (holotype, SYAU-FUNGI- 062) D basidia and basidioles E caulocystidia F basidiospores G cheilocystidia H, I Melanoleuca pallidorosea (holotype, SYAU-FUNGI- 058) H basidiospores I basidia and basidioles. Scale bars: 10 μm.