Lyophyllum shimeji (Kawam.) Hongo

Lyophyllum shimeji (Kawam.) Hongo View in CoL , Trans. Mycol. Soc. Japan 12 (2): 90 (1971)

Figs 7 C, D View Figure 7 , 10 View Figure 10 , 11 View Figure 11

Description.

Pileus 2.0–3.0 cm diameter, fleshy, fragile, hemispherical, becoming convex with age, abundant black floccus on the surface, dry, dark orange (# 756450), slightly depressed of center, deflexed to inflexed of margin; pileus context thick, 0.5–0.7 cm wide, white (# fcfcfc). Lamellae moderately close together, arcuate, subdecurrent to decurrent, broad, white (# fcfcfc), unchanging color when injured, 3–4 tiers, 0.3–0.4 cm wide, edge even or entire. Stipe 3.0–5.1 × 1.0– 1.4 cm, cylindrical to clavate, grayish yellow (# 89877 b) on the surface, tapering upwards, smooth; stipe context white (# fcfcfc), unchanging in color when injured. The odor and taste were not distinctive.

Basidiospores [75 / 2 / 2] 5.4–7.3 × 4.6–6.6 μm, (Q = 1.0–1.3, Qm = 1.10 ± 0.19), av. 6.03 ± 0.38 × 5.55 ± 0.65 μm, globose, subglobose to broadly ellipsoid, smooth. Basidia 32–41 × 6–9 μm (N = 20), av. 36.2 ± 3.8 × 8.3 ± 1.15 μm, mostly 4 - spored, rarely 2 - spored, sterigmata long 3.1–4.5 μm, sometimes with basal clamp connections, clavate, siderophilous granulations. Subhymenium is composed of moderately thin-walled hyphae, 15–30 μm thick, with 2–3 layers of ovoid, fusiform to narrowly cylindrical hyphae, 5–8 × 3–4 μm. Hymenophoral trama regular, 120–180 μm wide, consisting of thin and hyaline hyphae, some with clamp connections, narrowly cylindrical hyphal elements 2–4 μm wide. Cheilocystidia 15–22 (– 26) × 3–5 μm, av. 20.6 ± 4.4 × 4.7 ± 1.1 μm, narrowly cylindrical or narrowly clavate, thin-walled. Pleurocystidia were 16–20 × 3–5 μm in size and av. 18.6 ± 3.7 × 3.7 ± 0.4 μm, narrowly cylindrical or narrowly clavate, thin-walled. Pileipellis is an interwoven trichodermium composed of almost hyaline interwoven filamentous hyphae, terminal cells 2–4 μm wide, almost cylindrical to subcylindrical, occasional hyphal tips flexuous and sometimes inflated, and some with clamp connections. Stipitipellis composed of appressed, parallel, thin-walled, 3–6 μm wide. Clamp connections are present at some septa in the pileipellis, lamellae, and stipitipellis.

Habitat.

Clustered in the Quercus , Pinus , and mixed Picea and Fagus forests. Known from China, Japan, Sweden, Finland, and Norway ( Fujita et al. 1982; Kawai 1997; Yamanaka 2009).

Edibility.

This mushroom is highly appreciated and is cultivated worldwide.

Additional materials examined.

China • Chongqing Municipality, elev. 1,872 m, 12 October 2023, Tong Lv, HKAS 135647 View Materials ; ibid, 12 October 2023, Tong Lv, HKAS 135648 View Materials .

Notes.

The originally described Lyophyllum shimeji was from Japan as Tricholoma shimeji Kawam. ; it is a famous edible mushroom ( Fujita et al. 1982; Kawai 1997; Yamanaka 2009). However, the description of L. shimeji is incomplete, lacking both macroscopic and microscopic characteristics. In this study, we meticulously provided the comprehensive and detailed characteristics of L. shimeji , enabling more precise and unequivocal identification of this species. This thorough analysis ensures that future taxonomic studies and research endeavors can accurately distinguish L. shimeji from other similar fungal species, thereby facilitating a deeper understanding of its ecological role and potential applications in culinary and scientific contexts.