Pluteus granularis Peck

Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao & Li, Yu, 2025, Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species, IMA Fungus 16, pp. e 154329-e 154329 : e154329-

Pluteus granularis Peck , Ann. Rep. N. Y. St. Mus. Nat. Hist. (1885: 135)

Figs 18 I, J , 22

Description.

Basidiomata medium to large-sized. Pileus 30–51 mm diam; plano-convex to convex, slightly obtuse raised in the middle; yellow (10 YR 6 / 6) to yellow-brown (10 YR 5 / 6), with brown (5 YR 3 / 6) warped scales attached to the surface, the middle scales densely forming a vein-like, gradually becoming sparser toward the margin, with triangular scales toward the margin. Context white (10 P 9 / 2) and odorless. Lamellae free, 4–6 mm wide, crowded, yellowish-brown (2.5 YR 4 / 6), unequal, thin, ventricose, white and even to flocculose edges. Stipe 32–95 × 3–8 mm, fibrous, clavate, hollow, slightly expanded at the base, white (10 P 9 / 2) overall, with denser brown (10 YR 3 / 6) cilia on the middle to lower portion. Spore print unknown.

Basidiospores [60 / 2 / 1] 5.5–6.0 (– 6.5) × 4.5–5.0 µm, avL × avW = 5.7–6.0 × 4.6–4.8 µm, Q = 1.10–1.30 µm, avQ = 1.20 µm, subglobose, broadly ellipsoid to ellipsoid, smooth, slightly pinkish, thick-walled. Basidia 23–28 × 8–11 μm, broadly clavate, thin-walled, 4 - sterigmate, and hyaline. Pleurocystidia 55–83 × 15–33 μm, scattered, rare, two forms, one fusiform, with apical finger-like projections, 3–6 μm long, the other narrowly clavate to clavate, with an obtusely rounded apical portion, thin-walled, smooth, partly with brown intracellular pigment. Lamellar edge sterile. Cheilocystidia 34–65 × 13–22 μm, abundant, clustered, broadly clavate to clavate, apically obtuse, thin-walled, smooth, hyaline. Pileipellis a trichohymeniderm composed of narrowed fusiform and clavate elements, with terminal elements 130–216 × 17–31 μm, often aggregated into bundles, pointed towards the apex, with brown intracellular pigment, thin-walled, smooth. Stipitipellis a cutis, hyphae 4–6 μm diam, cylindrical, hyaline, thin-walled. Caulocystidia 36–55 × 13–19 μm, scattered, composed of long clavate to clavate vesicles, partly containing brownish pigment, thin-walled, smooth. Clamp connections absent in all tissues.

Habitat.

Scattered on very rotten decaying wood in broad-leaved forests ( Q. mongolica ).

World distribution.

USA ( Peck 1885, 1899; Murrill 1917; Kauffman 1918; Bessette et al. 1997; Justo et al. 2011 b), Turkey ( Kaygusuz et al. 2019), China ( Yang 2011).

China distribution.

Jilin Province, Sichuan Province, Yunnan Province, Tibet Autonomous Region ( Yang 2011).

Additional specimens examined.

CHINA • Jilin Province, Quanyang Township, Beigang , latitude and longitude: 43°02'2.06"N, 127°58'44.69"E; Scattered on very rotten decaying wood in broad-leaved forests ( Q. mongolica ); 22 August 2021, Z. X. Qi, FJAU 66612 (Collection no.: Qi 395) (ITS: PQ 810758 , LSU: PQ 810735 , tef 1: PQ 811045 ) .

Notes.

Peck reported P. granularis in 1885, and the species has been reported by several people since ( Peck 1885, 1899; Murrill 1917; Kauffman 1918; Bessette et al. 1997; Justo et al. 2011 b; Xu 2016; Kaygusuz et al. 2019). Summarizing their description of P. granularis , it can be found that it is characterized by an intense dark brown granular stipe and predominantly with conspicuous rugose-wrinkled, granulose pileus, pleurocystidia with apical mucilage. Our specimens are overall similar to their descriptions, both having an intense dark brown granular stipe and predominantly with conspicuous rugose-wrinkled, granulose pileus, but there is a slight difference. The latter pleurocystidia vesicles frequently form 1–3 small irregular horns apically and, if hornless, usually have mucilage apically. In the former, only 1 small irregular horn is observed and there is no mucilage.

Morphologically, P. granularis is very similar to P. umbrosus , as discussed in detail in the notes on P. umbrosus . The phylogeny shows that P. granularis from China clustered in the same branch as P. granularis from the USA with high support (MLB = 98, BPP = 1, Fig. 3 ). Here we report P. granularis from China, a common species.

Figures

Figure 3. Phylogenetic tree of the / umbrosus clade and / pantherinus lineage of the sect. Hispidoderma. The best tree from the ML and BI analysis of the ITS + tef 1 dataset. The two values of internal nodes respectively represent the Maximum Likelihood bootstrap (MLBP) / Bayesian posterior probability (BIPP). Nodes with a bootstrap probability (BP) ≥ 80 and a Bayesian posterior probability (PP) ≥ 0.80 are indicated in the phylogram. This study species is in bold and red font.

Figure 18. Basidiomata features. A – C. Pluteus costatus (A, B. FJAU 66589, C. FJAU 66618). D, E. P. umbrosus (FJAU 66590). F – H. P. umbrosoides (FJAU 66615). I, J. P. granularis (FJAU 66612). A – C. Photos by Di-Zhe Guo. D, E. Photos by Jia-Jun Hu. C, F – H. Photos by Gu Rao. I, J. Photos by Zheng-Xiang Qi. Scale bars: 1 cm.

Figure 22. A. Macroscopic characteristics of Pluteus granularis. B. Basidiospores. C. Pileipellis elements. D. Cheilocystidia. E. Caulocystidia. F. Basidia and Pleurocystidia. G. Pleurocystidia. Scale bars: 1 cm (A); 5 µm (B); 10 µm (D – G); 20 µm (C).