Infundibulicybe phaeocentralis L. Fan & Y.X. Zhang

Zhang, Yu-Xin, Mao, Ning, Li, Ting & Fan, Li, 2024, Two new species of Infundibulicybe (Omphalinaceae, Agaricales) from northern China, Phytotaxa 649 (2), pp. 193-210 : 203-205

Infundibulicybe phaeocentralis L. Fan & Y.X. Zhang sp. nov. Fig. 5

MycoBank:—MB852896

Diagnosis:—Basidiomata small to medium; pileus 2.6–5.4 cm diam, infundibuliform, dry, smooth, brick red to reddish brown, stipe hollow, yellowish brown, surface with inconspicuous longitudinal fibrils; shorter basidiospores (6–)6.5– 8(–8.5) × 4–6 μm and bigger basidia 25–40 × 6–7.5 μm.

Etymology:— phaeocentralis , refers to the darker center of the pileus.

Holotype:— CHINA. Shanxi Province, Guancen Mountain, on soil, in mixed forest of Larix gmelinii var. principis-rupprechtii and Picea asperata , 2 September 2022, J.Z. Cao CF1197 ( BJTC FM 2899) .

Description:— Basidiomata small to medium, clitocyboid. Pileus 2.6–5.4 cm diam, infundibuliform; dry, smooth, glabrous, brick red (#c2847a) to reddish brown (#8c564a), center and margin always darker, deep reddish brown (#67393b), margin straight. Lamellae long-decurrent, yellowish white (#f2f6b6) to deep cream (#d2b86b), moderately crowded, with 1 to 4 tiers of lamellulae, edges smooth and concolorous with faces. Stipe 3.7–5.7 × 0.6–0.9 cm, centrally attached, cylindrical, coarser towards the base, hollow, surface with inconspicuous longitudinal fibrils, yellowish brown (#a97e3d), base inflated with abundant white tomentum. 5 % KOH on the surface of the dried pileus produced no color change.

Basidiospores (6–)6.5–8(–8.5) × 4–6 μm, Q=(1.2)1.3–1.6(1.8), Qm=1.4±0.1, ellipsoidal to broadly ellipsoidal in face view, lacrymoid in lateral view, hyaline, smooth, inamyloid, cyanophilous, color not changing in KOH. Basidia 25–40 × 6–7.5 μm, clavate, hyaline, usually 4-spored, sometimes 2-spored, sterigmata 2.5–5 μm long. Cystidia absent. Lamellar trama regular; hyphae 4–10 µm wide, colorless, hyaline, cylindrical. Pileipellis a cutis composed of repent, cylindrical, subparallel, septate, thin-walled hyphae containing yellowish brown pigment 4.5–11.5 μm diam. Stipitipellis a cutis composed of subparallel cylindrical hyphae 4–10 μm diam. Clamp connections present in all parts of the basidiomata.

Ecology and distribution:—on soil of a mixed forest of Larix gmelinii var. principis-rupprechtii and Picea asperata , only known from Shanxi Province, northern China.

Additional specimens examined:— CHINA. Shanxi Province, Ningwu County, Guancen Mountain, on soil, in mixed forest of Larix gmelinii var. principis-rupprechtii and Picea asperata , 14 August 2017, H. Liu 1-LH170731 (BJTC FM402); CHINA. Shanxi Province, Ningwu County, on soil, in mixed forest of Larix gmelinii var. principis-rupprechtii and Picea asperata , 5 July 2022, H. Liu LH1563 (BJTC FM2067); CHINA. Shanxi Province, Ningwu County, Luya Mountain, elev. 2,293m, 111°58’17’’E, 38°47’58’’N, 16 August 2023, H.Y. Fu, H.M. Ji MS270 (BJTC FM3215).

Notes:— Infundibulicybe phaeocentralis formed an isolated position in our phylogenetic trees ( Figs. 1 , 2 ), which strongly supported its uniqueness. The new species is very similar to the samples of I. rufa that are also characterised by a red-brown cap ( Zhao et al. 2016). We also recognized the occurrence of I. rufa in the northern region of Shanxi Province in this study. However, most of the Shanxi samples of I. rufa supported by our molecular analysis clearly lack the red-brown in the cap, and are, instead, brown or yellow-brown, and sometimes a shade of purple-brown ( Fig. 6 , k). Thus, both of the two species are easily separated from each other by the color of the basidiomata in the area of Shanxi Province. Infundibulicybe squamulosa , originally described from Europe, and confirmed from China before this study ( He & Yang 2023), is another species similar to Infundibulicybe phaeocentralis in morphology, and this species is also distributed in Shanxi Province ( Fig. 6 , l–m). Actually, the two species are impossible to separate from each other by morphology alone based on the examination of the Shanxi samples in this study. However, I. squamulosa has been recorded only in the forest of pure Pinus tabuliformis in the lowland area in Shanxi Province, whereas I. phaeocentralis is exclusively found in the mixed forest of Picea sp. and Larix sp. in alpine or subalpine regions in this province. Infundibulicybe bispora and I. gibba are phylogenetically related to I. phaeocentralis according to the multilocus phylogeny ( Fig. 2 ). Morphologically, Infundibulicybe bispora can be distinguished from I. phaeocentralis by its white lamellae, mostly 2-spored basidia, longer sterigmata (4–10 μm) and longer basidiospores (6–11.5 × 4–6 μm) ( He & Yang 2023). I. gibba is differentiated by its tan, pinkish tan, or flesh-colored pileus, whitish, off-white, or very pale stipe and smaller basidiospores (5–9 × 3.5–6 μm) ( Harmaja 2003).

Figures

FIGURE 1. The ML phylogenetic tree based on the ITS sequences of Infundibulicybe. Clitopaxillus fibulatus and Pseudoclitocybe cyathiformis are the outgroups. Values at the node represent ML bootstrap (≥ 70 % BS, left) and Bayesian posterior probability (≥ 0.99 PP, right) support. Our specimen sequences are printed in bold and the new species sequences are highlighted in blue in the tree.

FIGURE 2. The ML phylogenetic tree based on the combined LSU-TEF1-RPB1-RPB2-ATP6 sequences of Infundibulicybe.Clitopaxillus fibulatus and Pseudoclitocybe cyathiformis are outgroups. Values at the node represent ML bootstrap (≥ 70 % BS, left) and Bayesian posterior probability (≥ 0.99 PP, right) support. Our specimen sequences are printed in bold and the new species sequences are highlighted in blue in the tree.

FIGURE 5. Infundibulicybe phaeocentralis. a. Basidiomata (BJTC FM2899, holotype). b. Basidia. c. Pileipellis. d. Basidiospores. Scale bars: a = 10 mm, b, c, d = 5 μm. Photos by: Jinzhong Cao, drawings by: Yuxin Zhang.

FIGURE 6. Basidiomata of Infundibulicybe species. a–c. I. alkaliviolascens (BJTC FM1653, BJTC FM1658, BJTC FM3396). d–f. I. gibba (BJTC FM682, BJTC FM757, BJTC FM1706). g–j. I. hongyinpan (BJTC FM187, BJTC FM216, HSA391, BJTC FM394).k. I. rufa (BJTC FM562). l–m. I. squamulosa (BJTC FM2451, BJTC FM2452). Scale bars: a–m = 1cm. Photos by: Hong Liu, Jinzhong Cao.