Friday, September 30, 2022

[Fungi • 2022] Gymnopus omphalinoides & G. schizophyllus (Agaricales: Omphalotaceae) • Emending Gymnopus sect. Gymnopus by including Two New Species from southern China


 Gymnopus omphalinoides J.P. Li, T.H. Li & Y. Li,

in Li, Antonín, Gates, Jiang, ... et Deng, 2022. 

Abstract
Based on phylogenetic analyses, some newly studied Chinese mushroom specimens were found to represent two distinct species within the genus Gymnopus. Along with G. fusipes (sect. Gymnopus) they form a distinct clade with high support, although their macromorphological characters seem to be closer to members of Gymnopus sect. Levipedes or sect. Vestipedes (Collybiopsis). When examined in detail, their micromorphological characters, especially the type of pileipellis, support them as new members of G. sect. Gymnopus. Therefore, two new species, G. omphalinoides and G. schizophyllus, and the emended circumscription of sect. Gymnopus are proposed in this paper. Detailed morphological descriptions, colour photos, illustrations of the two new species, morphological comparisons with similar taxa and the molecular-phylogenetic analyses of the combined nrITS and nrLSU data are presented. A key to the known species of G. sect. Gymnopus is also presented.

Keywords: Morphology, new taxa, phylogeny, taxonomy

Basidiomata of Gymnopus omphalinoides
a GDGM 78483 b GDGM 78318 holotype! (with magnifying slightly longitudinally striate stipe)
c KUN-HKAS 107312 d, e GDGM 44411 f HMJU 00506.
a photographed by M. Zhang b photographed by L.Q. Wu, c photographed by X.H. Wang d, e photographed by J.P. Li f photographed by J.Z. Xu. For a detailed display, the slightly longitudinally striate stipe is magnified in b, and the split lamellar edge is magnified in e, f. Scale bars: 1 cm.

 Gymnopus omphalinoides J.P. Li, T.H. Li & Y. Li, sp. nov.
 
Diagnosis: Differs from G. volkertii Murrill in its striate or grooved pileus and smaller basidiospores (4.0–5.5 × 2.5–3 μm). Basidiomata mainly gregarious on decayed wood in broadleaf forest; pileus disc reddish orange to dark brown becoming paler with age; lamellae broad, adnate and ventricose; stipe glabrous.

Etymology: The epithet ‘omphalinoides’ (Lat.) refers to the omphalinoid or Omphalina-like basidiomata of the new species.


Basidiomata of Gymnopus schizophyllus
a GDGM 77038 b GDGM 76287 c GDGM 77165 holotype! d KUN-HKAS 96494
a, c photographed by J.P. Li b photographed by H.S. Wen d photographed by S.H. Li. For a detailed display, the split lamellar edge is magnified in a. Scale bar: 1 cm.

 Gymnopus schizophyllus J.P. Li, T.H. Li & Y. Li, sp. nov.

Diagnosis: Differs from G. omphalinoides in its more or less depressed to slightly umbilicate pileus and more often split lamellar edge. Basidiomata mainly gregarious on decayed wood in broadleaf forest; pileus often pale orange to light brown; lamellae, adnate and generally split at the edge; stipe glabrous.

Etymology: The epithet “schizophyllus” (Lat.) refers to the split edge of lamellae which is not so common in the genus.

 
Ji-Peng Li, Vladimír Antonín, Genevieve Gates, Lu Jiang, Tai-Hui Li, Yu Li, Bin Song and Chun-Ying Deng. 2022. Emending Gymnopus sect. Gymnopus (Agaricales, Omphalotaceae) by including Two New Species from southern China. MycoKeys. 87: 183-204. DOI: 10.3897/mycokeys.87.76125