Pluteus spaniophyllus Z. X. QI, B. Zhang & Y. Li, 2025

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-

publication ID

https://doi.org/10.3897/imafungus.16.154329

DOI

https://doi.org/10.5281/zenodo.16577323

persistent identifier

https://treatment.plazi.org/id/B9E5F9BF-D43B-59F8-986A-3CE5B4CC9C66

treatment provided by

by Pensoft

scientific name

Pluteus spaniophyllus Z. X. QI, B. Zhang & Y. Li
status

sp. nov.

Pluteus spaniophyllus Z. X. QI, B. Zhang & Y. Li sp. nov.

Figs 5 H, I View Figure 5 , 9 View Figure 9

Etymology.

The species epithet “ spaniophyllus ” (Latin) refers to the sparseness of the lamellae.

Diagnosis.

Pluteus spaniophyllus differs from P. jilinensis by its velvety pileus, sparse lamellae, smaller basidiospores, and their ITS genetic distance is 0.008 (SE = 0.004) and tef 1 genetic distance is 0.008 (SE = 0.004).

Holotype.

CHINA • Jilin Province, Cold Jungle National Nature Reserve ; Solitary on rotting wood in broad-leaved forests; 7 August 2021, G. Rao, FJAU 66593 (Collection no.: Rao 1292) (ITS: PP 516619 , LSU: PP 516669 View Materials , tef 1: PP 551605 ).

Description.

Basidiomata small-sized. Pileus 17 mm diam; hemispherical; white to light yellow (2.5 Y 9 / 10), slightly with brown velvety or pruinose on the surface of the center (7.5 YR 8 / 6); margin radial translucently striate. Lamellae pale flesh – pink (5.0 R 9 / 6), free, relatively sparse, thick, unequal, slightly ventricose, 4–7 mm wide, with even edges; lamellar edge white. Stipe 14 × 3 mm, cylindrical, with a bulbous base, fibrous, surface with white pruinose (2.5 Y 9 / 12). Odorless. Spore prints pink.

Basidiospores [60, 1, 1] (– 6.5) 7.0–7.5 (– 8.0) × 6.0–6.5 (– 7.0) μm, avL × avW = 7.0–7.3 × 6.2–6.5 µm, Q = 1.00–1.33 μm, avQ = 1.07–1.10 μm, globose, subglobose to broadly ellipsoid, pale pink, smooth, thin-walled. Basidia 23–30 × 8–11 μm, clavate to broadly clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 53–91 × 18–31 μm, scattered, fusiform to subfusiform, apically obtuse, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 25–70 × 11–27 μm, abundant, clustered, similar in form to pleurocystidia, narrowly to broadly fusiform, broadly subfusiform, some apical with small irregular horns or mucronate, thin-walled, hyaline. Pileipellis a trichohymeniderm, with terminal elements 51–92 × 12–28 μm, broadly clavate or fusiform, thin-walled, with brown intracellular pigment. Stipitipellis a cutis, hyphae 3–12 µm diam, cylindrical, hyaline, thin-walled. Caulocystidia 28–47 × 9–18 μm, numerous, occurring in clusters, cylindrical to broadly clavate to broadly fusiform, or narrowly utriform, hyaline, thin-walled. Clamp connections absent in all tissues.

Habitat.

Solitary on rotting wood in broad-leaved forests.

World distribution.

China.

China distribution.

Jilin Province.

Notes.

Pluteus spaniophyllus is characterized by its small basidiomata, hemispherical pileus ranging from white to light yellow, with brown velvety on the surface, margin radial translucently striate, sparse lamellae, and a white pruinose on the stipe base, which is inflated and nearly bulbous.

Morphologically, P. spaniophyllus shares greatest similarity with P. hubreg tseorum and P. boudieri , but can be distinguished from each by several key features. P. spaniophyllus differs from P. hubregtseorum by its fleshy brown pileus, in contrast to the yellow-to-brownish-gold pileus of the latter. Additionally, P. spaniophyllus produces pale flesh-pink and sparsely arranged lamellae, whereas those of P. hubregtseorum are pale pink to flesh pink and crowded. The species also differ in their geographic distribution, with P. spaniophyllus occurring in East Asia ( China) and P. hubregtseorum in Australia ( Ševcíková et al. 2021), further supported by an ITS genetic distance of 0.023 (SE = 0.006).

P. spaniophyllus bears a closer resemblance to the white-capped P. boudieri , from which it is primarily distinguished by pileipellis morphology. P. boudieri exhibits thin, filamentous, light-brown pileipellis hyphae with generally cylindrical or subfusiform terminal elements ( Vellinga and Schreurs 1985; Orton 1986). In comparison with P. atriavellaneus , P. spaniophyllus has a white to light yellow pileus, grows on decaying wood, and is distributed in East Asia ( China), whereas P. atriavellaneus is characterized by a dark fuliginous to avellaneous, hygrophanous and finely pubescent pileus, growth on humus, and distribution in North America ( USA) ( Murrill 1917). Finally, P. spaniophyllus is distinguished from P. avellaneus by its central light yellow pileus with white margins and radial striate (distributed in East Asia, China), in contrast to the centrally paler, hygrophanous pileus with non-striped margins of P. avellaneus (distributed in North America, USA) ( Murrill 1917).

In the phylogenetic analysis, P. spaniophyllus (specimen FJAU 66593 from China) is strongly supported as a sister taxon to P. aff. semibulbosus (MLB = 98, BPP = 1, Fig. 2 View Figure 2 ). These species are further distinguished by several morphological features: P. spaniophyllus produces smaller basidiomata (17 mm) with sparser lamellae and cheilocystidia bearing small irregular apical horns, whereas P. aff. semibulbosus forms larger basidiomata (43 mm) with denser lamellae and cheilocystidia lacking irregular apical horns (Table 3 View Table 3 ). Molecular evidence further supports their separation, with an ITS genetic distance of 0.009 (SE = 0.004) and tef 1 genetic distance of 0.004 (SE = 0.003).

Kingdom

Fungi

Phylum

Basidiomycota

Class

Agaricomycetes

Order

Agaricales

Family

Pluteaceae

Genus

Pluteus