Micropsalliota digitatocystis R.L. Zhao, J.X. Li & M.Q. He, 2021

Li, Jia-Xin, He, Mao-Qiang & Zhao, Rui-Lin, 2021, Three new species of Micropsalliota (Agaricaceae, Agaricales) from China, Phytotaxa 491 (2), pp. 167-176 : 171-172

Micropsalliota digitatocystis R.L. Zhao, J.X. Li & M.Q. He , sp. nov. Figure 2

Fungal Name: FN570747

Etymology:refers to the pleurocystidia with a digitate apical appendix.Diagenesis:this new species is characterized by its brownish, fibrillose scales on pileus, stipe heavily covered white tomentose-flocculose, a needle-like pleurocystidia.

Holotype: CHINA, Yunnan Province, Lushui County, Gaoligong National Natural Reserve, 8 July 2018, Zhi-Ling Ling , ZRL20180564 ( HMAS290750 ).

Macroscopic description: Pileus 16–74 mm in diam., convex to applanate, subumbonate, margin crenate, surface dry, covered with fibrillose scales, slightly erect, denser at disc, scanty towards the margin, reddish brown, background white or light gray. Context up to 2 mm thick at disc. Lamellae free, crowded, with 4 series of lamellulae, 3–4 mm broad, grayish brown. Stipe 60–90 × 5–8mm, cylindrical with a slightly thickened base; surface above the ring white, smooth to fibrillose, decreasing with age, below the ring heavily covered with fibrils, white, yellowish-brown when bruised or cut. Annulus pendent, single, membranous, white, edge entire, persistent, up to 8–20 mm. Odor not distinctive.

Microscopic description: Basidiospores 5.8–7.4 × 4–4.6 μm, [x = 6.9 ± 0.3 × 4.5 ± 0.2, Q = 1.5–1.8, Q m = 1.5 ± 0.085, n = 22], ellipsoid, sometimes amygdaliform, without germ pore, brown. Basidia 14.1–20.4 × 7.6–9.3 μm, clavate, hyaline, 4-spored. Cheilocystidia 37.4–52 × 9–16.4 μm, cylindrical to subclavate, slightly swollen at the middle, subcapitate to capitate, smooth, hyaline. Pleurocystidia present, with the similar size to basidia, nevertheless, carrying with a needle-like apex up to 4–5μm. Pileipellis composed of hyphae of 8–19 μm in diam., constricted at the septa, smooth, with internal brown pigment. Annulus composed of hyaline hyphae 5–18 μm in diam., smooth.

KOH reaction: unknown.

Habit and habitat: solitary on soil in forest.

Known distribution: China.

Additional material examined: CHINA, Guangxi Zhuang Autonomous Region , Leye County, 7 August 2017, Mao-Qiang He, GX 20170688 ( HMAS290751 ) .

Notes: Micropsalliota digitatocystis , M. globocystis , M. megarubescens , M. pseudoglobocystis and M. purpureobrunneola share similar morphological characteristics and they clustered together in the phylogenetic tree. However, M. digitatocystis is characterized by larger basidiomata (pileus diam. 18–74 mm, stipe 60–90 × 5–8mm), pileus margin dentate, floccose tomentose stipe bellow the annulus and digitate pleurocystidia. Micropsalliota globocystis and M. digitatocystis are morphologically very similar, but the former is characterized by its purple to purplish brown, grayish brown or reddish-brown pileus, and usually M. digitatocystis , presents light gray pileus. However, when M. digitatocystis has a reddish-brown pileus it also differs from M. globocystis in having digitate pleurocystidia. Micropsalliota megarubescens differs in having white to cream pileus becoming grayish brown with age and a strong red discoloration when touching or bruising. Micropsalliota pseudoglobocystis differs from M. digitatocystis , in having small basidiomata as well as small basidiospores (4.5–6 × 2.5–3.2μm) ( Wei et al. 2015). Micropsalliota purpureobrunneola is distinguished from M. digitatocystis , in having small basidiomata (pileus 5–12 mm) and purple or purplish-brown scales ( He et al. 2020).

Figures

FIGURE 2. Micropsalliota digitatocystis (HMAS290750, holotype), (A–B) basidiomata in field (C) cheilocystidia; (D) pleurocystidia; (E) basidia; (F) basidiospores; (G) annulus hyphae; (H) pileipellis hyphae. Bars: A, B = 1 cm; C–G = 20 μm; H = 25 μm.