Spodocybe alpina L.P. Tang & J. Ma

Ma, Jing, Zhang, Guo-Li, Zhang, Wen-Hao, Pu, Yun-Ju & Tang, Li-Ping, 2024, A contribution to the knowledge of the genus Spodocybe (Hygrophoraceae, Agaricales) in China, Phytotaxa 652 (1), pp. 47-58 : 50-52

Spodocybe alpina L.P. Tang & J. Ma , sp. nov. ( Figs. 2a – b , 3a , 4a )

Chinese name: Ả山灰ȅ杯伞

MycoBank:—MB844214

Diagnosis:—Differs from S. bispora in having smaller basidiomata and smaller basidiospores, growing on the ground of dark coniferous forests.

Etymology:— “ alpina ” refers to the occurrence in high-elevation.

Holotype:— CHINA. Yunnan province: Yulong Naxi Autonomous prefecture (玉ÁaewNJÞ治县), Tai'an Town (kae乡), Observatory (天Ý台), on the soil of coniferous forests dominated by Pinus armandii and P. densata , 26°42.05'N, 100°2.12'E, elev. 3150 m, 27 July 2021, Wen-Hao Zhang 642 (MHKMU Zhang-642!, GenBank Acc. No. : nrLSU = ON595779, ITS = ON595770).

Description:— Basidiomata medium, texture flexible. Pileus 2−3.5 cm diam., nearly explanate, center depressed; surface finely tomentose, white (1B1) when young, grey-white (3B1) to grey-brown (5D1−2) when mature; context dirty white (2A1), thick about 0.3 cm wide. Lamellae decurrent, slightly crowded, white (1B2), about 0.2 cm wide. Stipe 5.5−6.5 cm long, 0.4−0.6 cm in diam., cylindrical, hollow, concolorous with pileus at apex part, gradually paler towards the base. Mycelial hyphae white.

Basidiospores [60/2/1] 4.5−6 × (2.5−) 3−3.5 μm, Q = 1.43−2.0, Q m = 1.73±0.18, ellipsoid to elongate, hyaline, smooth, thin-walled, inamyloid. Basidia 20−25 × 4.5−5.5 μm, clavate, thin-walled, usually 4-spored, occasionally 2- spored or 3-spored; sterigmata 2−4 μm long. Cystidia absent. Lamellar trama subregular, hyaline, consisting of hyphae 3–9 μm, thin-walled. Pileipellis a cutis, comprised of hyphae 3–11 μm wide, thin-walled or slightly thickened (about 1 μm). Pileitrama comprised of parallel hyphae 3–10 μm wide, thin-walled. Stipitipellis a cutis, comprised of hyphae 3–9 μm wide, thin-walled or slightly thickened (about 1 μm). Stipititrama comprised of parallel hyphae 3–10 μm wide, thin-walled. Mycelial hyphae 2–9 μm wide, thin-walled. Clamp connections present in all tissues.

Habit and habitat:—Usually scattered on the ground of dark coniferous forests dominated by Pinus armandii and P. densata .

Distribution:— CHINA: currently known only from Yunnan province (Dali city, Yulong Naxi Autonomous prefecture) at elevations ranging from 3,100 –4,100 m.

Additional material examined:— CHINA. Yunnan province: Dali City (大DZṁ), Cangshan (ẠƜ), XiaoCen Feng (小Ẹē), 26°68.23'N, 100°09.32'E, elev. 4,100 m, 20 July 2019, KUN-HKAS 112565 (Genbank Acc. No.: nrLSU = MW763015, ITS = MW762890).

Comments:— Spodocybe alpina was treated as an unknown species in He & Yang 2021 (KUN-HKAS 112565). This new species is distinguished by its medium basidiomata (2–3.5 cm diam), grey-brown stipe, ellipsoid to elongate basidiospores, basidia usually 4-spored, and usually scattered on ground in forests of P. armandii and P. densata . Currently, this taxon is known only in Yunnan province, and is the only known one with the highest distribution elevation (3100−4100 m). Spodocybe alpina is likely to be confused with S. bispora . Both have a nearly smooth and grey-brown pileus, but S. bispora differs in its larger basidiomata (3−5 cm vs. 2−3.5 cm), larger basidiospores (7−8.5 × 3−4 μm vs. 4.5−6 × 3−3.5 μm), longer basidia (20–30 × 4–5.5 μm vs. 20−25 × 4.5−5.5 μm), usually 2-spored, and gregarious on the ground of broad-leaved or mixed forests at lower altitudes (1900−2700 m vs. 3100−4100 m).

Figures

FIGURE 2. Basidioma of four taxa in Spodocybe from southwest China. a, b S. alpina (MHKMU Zhang-642, holotype); c, d S. bispora (c MHKMU Huang-093, d MHKMU Huang-078); e–g S. microspora (e–g MHKMU Mu-127, holotype); h S. rugosiceps (HKAS 69830) (a, b photos by W.H. Zhang; c, d photos by H.Y. Huang; e–g photos by M. Mu; h photos by L.P. Tang).

FIGURE 3. Basidiospores of four taxa in Spodocybe from southwest China. a S. alpina (MHKMU Zhang-642, holotype); b, c S. bispora (b HKAS 73310, holotype; c MHKMU Huang-093, MHKMU Tang-3049); d S. microspora (MHKMU Mu-127, holotype; MHKMU Pu- 008, MHKMU Niu-080); e S. rugosiceps (HKAS 71071); Bars: a–e = 20 μm. (a–e photos by J. Ma).

FIGURE 4. Microscopic features of Spodocybe alpina and S. microspora a, b Basidia. c, d Pileipellis. a from S. alpina; b–d from S. microspora. Bars: a, b =20 μm, c, d = 40 μm. (a–d photos by J. Ma).