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| Collybiopsis subpolygramma; Collybiopsis fucata; Collybiopsis dentata J.Q. Yan, L. Ding, & S.N. Wang, in Ding, Zhong, Zeng, Wang et Yan, 2025. |
Abstract
Four new species of Collybiopsis, namely C. subpolygramma, C. fucata, C. dentata, and C. latispora, were discovered in the subtropical regions of China. These species were identified based on morphological characteristics and molecular analysis. Morphologically, C. subpolygramma is characterized by its pileal surface, white in color with a light brown center; slender, cylindrical cheilocystidia; and absence of pleurocystidia. C. fucata is recognized by the reddish-brown, hygrophanous pileus; adnate to adnexed lamellae; and relatively broad basidiospores. C. dentata is identified by free lamellae, fusiform to utriform pleurocystidia, and relatively broad basidiospores. C. latispora is distinct by relatively broad basidiospores and a minute, snow-white ring or ruff at the stipe base. In the phylogenetic analysis based on combined ITS and LSU sequences, the four new species formed distinct and stable branches (BI-PP = 1; ML-BP = 100%), respectively. Collybiopsis subpolygramma formed a sister lineage with C. polygramma. The new species C. fucata, C. dentata, and C. latispora were found to be nested within the C. ramealis species complex clade. Detailed descriptions, color photos, and a key to related species are presented.
Key words: Basidiomycetes, new taxa, phylogeny, taxonomy
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| Collybiopsis subpolygramma. A–C. Basidiomata; D–F. Basidiospores; G. Basidia; H–J. Cheilocystidia; K. Pileipellis; L. Caulocystidia. All microscopic structures were observed in 5% KOH, and 1% Congo red was used as the stain. Scale bars: 30 mm (A–C); 5 µm (D–F); 20 µm (G); 30 µm (H–I); 20 µm (J); 30 µm (K, L). |
Collybiopsis subpolygramma J.Q. Yan, L. Ding, & S.N. Wang, sp. nov.
Etymology. Referring to its similarity to C. polygramma, that pileus is sulcate.
Diagnosis. This species is characterized by its pileal surface, white in color with a light brown center; crowded and occasionally forked lamellae; white to black-brown stipe; slender cylindrical cheilocystidia; basidia mainly 2-spored; and absence of pleurocystidia.
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| Collybiopsis subpolygramma. A–C. Basidiomata Collybiopsis fucata. A–C. Basidiomata Collybiopsis dentata. A–C. Basidiomata |
Collybiopsis fucata J.Q. Yan, L. Ding, & S.N. Wang, sp. nov.
Etymology. Refer to the Latin “fucatus,” meaning “painted”—the lamellae edges are fucata.
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.
Collybiopsis dentata J.Q. Yan, L. Ding, & S.N. Wang, sp. nov.
Etymology. Refer to the Latin “dens,” meaning “tooth”—the lamellae edges are dentate.
Diagnosis. This species is characterized by white lamellae that are free, basidiospores 3.9–4.7 µm broad, fusiform to utriform pleurocystidia, and cheilocystidia measuring up to 30–71 × 17–29 µm.
Collybiopsis latispora J.Q. Yan, L. Ding, & S.N. Wang, sp. nov.
Etymology. Refer to the Latin “latus,” meaning “broad”—the species having wide basidiospores.
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.
Ling Ding, Ben-Jian Zhong, Hui Zeng, Sheng-Nan Wang, Jun-Qing Yan. 2025. Four New Species of Collybiopsis (Omphalotaceae, Agaricales) from subtropical regions of China. MycoKeys. 118: 289-311. DOI: doi.org/10.3897/mycokeys.118.155560 [11-06-2025]
