Collybiopsis fucata J. Q. Yan, L. Ding, & S. N. Wang, 2025

Ding, Ling, Zhong, Ben-Jian, Zeng, Hui, Wang, Sheng-Nan & Yan, Jun-Qing, 2025, Four new species of Collybiopsis (Omphalotaceae, Agaricales) from subtropical regions of China, MycoKeys 118, pp. 289-311 : 289-311

Collybiopsis fucata J. Q. Yan, L. Ding, & S. N. Wang sp. nov.

Fig. 3

Etymology.

Refer to the Latin “fucatus,” meaning “painted” — the lamellae edges are fucata.

Holotype.

China • Zhejiang Province, Lanni Lake, Qingtian County, Lishui City , 6 July 2021, Jun-Qing Yan, HFJAU 2535 .

Diagnosis.

This species is characterized by the reddish-brown, hygrophanous pileus; white lamellae that are adnate to adnexed; reddish-brown stipe with a white apex; basidiospores 3.9–5.2 µm broad; fusiform to utriform pleurocystidia; and cheilocystidia 25–65 × 11–31 µm.

Macrostructures.

Pileus 6.5–14 mm in diam., hemispherical when young, then becoming convex, applanate when mature, umbilicate at center, margin entire, surface smooth or with striations, hygrophanous, reddish-brown (8 D 4–5), with color fading from the center to the margin and gradually paling from the margin to the center as the hygrophanous effect disappears, center light brown (7 D 5–6). Lamellae adnate to slightly adnexed, distant, with 1– 2 types of lamellulae, white, with entire edges, concolorous with the lamellae. Stipe 4.0–8.9 × 0.5–1.0 mm, central, hollow, cylindrical, equal, darkening towards the base, white at the apex to reddish-brown (8 E 5–6) at the base, surface covered with white fibrils, no white mycelium observed at the base.

Microstructures.

Basidiospores in side view [n = 118] (6.7) 7.0–9.1 (9.7) × (3.3) 3.9–5.2 (5.4) µm (av = 8.1 × 4.4 µm, Q = (1.5) 1.6–2.1 (2.2) (Qm = 1.8 ± 0.1), ellipsoid to elongated-ellipsoid, in profile slightly curved or flattened on one side; in face view 4.0–5.0 (5.1) µm broad, ellipsoid to elongated-ellipsoid, thin-walled, hyaline, non-amyloid. Basidia 21–30 × 5.4–8.5 µm, clavate, 4 - or 2 - spored. Pleurocystidia 17–34 × 4.2–8.0 µm, abundant, fusiform, utriform, thin-walled, hyaline. Cheilocystidia 25–65 × 11–31 µm, abundant, with pedicellate spherical shapes, occasionally broad club-shaped or clavate, with short protuberances on the surface and occasionally branched, with pedicel 2.5–7.5 µm broad, branches 2.6–15 × 1.1–3.1 µm, thin-walled, hyaline. Pileipellis a cutis, with rameales-type structure, hyphal cells 2.1–8.6 µm broad. Stipitipellis a cutis, with numerous small protrusions on the hyphae, hyphal cells 2.9–13 µm broad, protrusions 3.2–13 × 1.5–6.1 µm, thin-walled. Clamp connections present.

Habitat.

Scattered or gregarious on decaying wood in mixed forests and broad-leaved forests.

Distribution.

China.

Additional specimens examined.

China • Hubei Province: Longmenhe Village, Xingshan County, Yichang City , 29 June 2024, Jun-Qing Yan, Lin-Gen Chen, Hong Chen, and Ling Ding, HFJAU 5343 ; Zhejiang Province: Lanni Lake, Qingtian County, Lishui City , 1 August 2021, Jun-Qing Yan, Bin-Rong Ke and Zhi-Heng Zeng, HFJAU 2653 .

Remarks.

Collybiopsis fucata is morphologically similar to C. californica (Desjardin) R. H. Petersen , C. filamentipes R. H. Petersen , and C. foliiphila (A. K. Dutta, K. Acharya & Antonín) R. H. Petersen within the C. ramealis complex, all having a cutis of pileipellis with rameales-type structure and cheilocystidia with rameales-type structure. However, C. californica has a longer stipe (10–46 mm long), narrower basidiospores (3.0–3.3 µm), smaller cheilocystidia (20–42 × 6–20 µm), and absence of pleurocystidia ( Desjardin 1987). Collybiopsis filamentipes has adnexed to subdecurrent lamellae, a longer stipe (12–21 mm), narrower basidiospores (2.5–3.5 µm), and narrower cheilocystidia (8–18 µm broad), clavate to broad clavate, occasionally stoutly dichotomous ( Petersen and Hughes 2021). Collybiopsis foliiphila has white pileus, lamellae often with rusty tawny to dark brick-colored spots, narrower basidiospores (3.0–3.7 µm), smaller cheilocystidia (28.6–31 × 9–12 µm), and absence of pleurocystidia ( Dutta et al. 2015).

Figures

Figure 3. Collybiopsis fucata. A – C. Basidiomata; D – F. Basidiospores; G. Basidia; H – I. Pleurocystidia; J – L. Cheilocystidia; M, N. Pileipellis; O. Stipitipellis. All microscopic structures were observed in 5 % KOH, and 1 % Congo red was used as the stain. Scale bars: 5 mm (A – C); 10 µm (D – F); 20 µm (G – I); 30 µm (J – O).