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

Fig. 5

Etymology.

Refer to the Latin “ latus, ” meaning “ broad ” — the species having wide basidiospores.

Holotype.

China • Fujian Province, Wuyishan Mountain , 12 August 2021, Qin Na, Yu-Peng Gai, HFJAU 3109 .

Diagnosis.

This species is characterized by white lamellae with a minute, snow-white ring or ruff at the stipe base; basidiospores 4.3–5.9 µm broad; subcylindrical, narrow fusiform, narrow utriform pleurocystidia; and cheilocystidia 16–47 × 13–24 µm.

Macrostructures.

Pileus 2.5–6.5 mm in diam., convex to plane, margin entire, sulcate towards margin, white, brownish-orange (7 C 3) at the center. Lamellae adnexed, distant, with 1– 2 types of lamellulae, white, edges serrate, concolorous with the lamellae. Stipe 2.1–4.2 × 0.4–0.7 mm, central, hollow, cylindrical, equal, light brown (7 D 5–6), white at approximately three-quarters of the base, surface covered with white pruinose, with minute snow white ring or ruff on stipe base.

Microstructures.

Basidiospores in side view [n = 43] (6.4) 6.7–8.1 (8.2) × (4.1) 4.3–5.9 (6.2) µm (av = 7.4 × 4.8 µm, Q = 1.3–1.6 (1.8) (Qm = 1.5 ± 0.09), ellipsoid to elongated-ellipsoid, in profile slightly curved or flattened on one side; in face view (4.3) 4.5–5.7 (7.3) µm broad, broadly ellipsoid, ellipsoid to elongated-ellipsoid, thin-walled, hyaline, non-amyloid. Basidia 16–28 × 5.1–8.6 µm, clavate, 2 - or 4 - spored. Pleurocystidia 18–37 × 4.4–7.3 µm, abundant, subcylindrical, narrow fusiform, narrow utriform, thin-walled, hyaline. Cheilocystidia 16–47 × 13–24 µm, abundant, pyriform, broad clavate, with pedicellate spherical shapes, with short projections on the surface, occasionally branched, with pedicel 3.1–6.6 µm broad, branches 2.7–11 × 1.2–3.1 µm, thin-walled, hyaline. Pileipellis a cutis, with rameales-type structure, hyphal cells 3.8–9.1 µm broad. Stipitipellis a cutis, hyphal cells 3.3–7.7 µm broad, thin-walled. Caulocystidia 21–47 × 3.4–9.7 µm, abundant, cylindrical, surface with protuberances or branches, thin-walled. Clamp connections present.

Ecology.

Scattered on dead branches in mixed forests.

Remarks.

Collybiopsis latispora is morphologically similar to C. californica , C. filamentipes , and C. foliiphila 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), narrower basidiospores (3.0–3.3 µm), and absence of pleurocystidia ( Desjardin 1987). Collybiopsis filamentipes has a longer stipe (12–21 mm), smooth, narrower basidiospores (2.5–3.5 µm), and cheilocystidia that are typically clavate to broad clavate, occasionally stoutly dichotomous ( Petersen and Hughes 2021). Collybiopsis foliiphila has lamellae often with rusty tawny to dark brick-colored spots, narrower basidiospores (3.0–3.7 µm), narrower cheilocystidia (9–12 µm), and absence of pleurocystidia ( Dutta et al. 2015).

Figures

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