Panus baishanzuensis L. Yue, B. Zhang & Y. Li, 2024

Yue, Lei, Chen, Junliang, Tuo, Yonglan, Qi, Zhengxiang, Liu, Yajie, He, Xiao Lan, Zhang, Bo, Hu, Jiajun & Li, Yu, 2024, Taxonomy and phylogeny of Panus (Polyporales, Panaceae) in China and its relationship with allies, MycoKeys 105, pp. 267-294 : 267-294

Panus baishanzuensis L. Yue, B. Zhang & Y. Li sp. nov.

Figs 4 , 5

Etymology.

The epithet ‘ baishanzuensis ’ refers to the type locality, Baishanzu National Park, of this species.

Diagnosis.

This species differs from closely-related species by pileus with concentric darker zones, crowded lamellae with cross-veins, shorter stipe, lack of pseudosclerotium, longer basidiospores, greater Q values, diverse and shorter cheilocystidia and smaller sclerocystidia.

Holotype.

China. Zhejiang Province: Lishui City, Qingyuan County, Baishanzu National Park , 27.62 ° N, 118.92 ° E, 28 July 2023, Yingkun Yang & Lei Yue, FJAU 67794 (GenBank accession no.: ITS: PP 273985, PP 273986, PP 273987; nLSU: PP 273975, PP 273976, PP 273977; tef- 1 α: PP 590553, PP 590554, PP 590555).

Description.

Basidiomata solitary, medium. Pileus 6–6.8 cm in diameter, thin, coriaceous, infundibuliformis or flared, ochre-brown (N 70 Y 99 M 60), with concentric darker zones, densely covered with brown (N 50 Y 80 M 30) farinaceus pilosus, stripe dense and slender, radially parallel distributed, margin sinuatus. Lamellae decurrent, crowded, pale yellow (A 60 M 00 C 00), with cross-veins and six tiers of lamellulae, edge entire. Stipe 2.3–3.1 × 0.3–0.6 cm, short clavate, excentric, solid, coriaceous, surface concolorous with the pileus or more often darker, with densely velutinus, slightly expanded at the apex. Pseudosclerotium absent. Context thin, up to 1 mm thick, white (N 00 Y 10 M 00), coriaceous, consisting of a dimitic hyphal system with skeletal hyphae.

Generative hyphae 2–3 μm diameter, cylindrical, not inflated, hyaline, thin-walled, frequently branched, with prominent clamp connections. Skeletal hyphae 2–3 μm diameter, sinuous cylindrical, hyaline, with a thick-walled and continuous lumen, unbranched. Basidiospores 7–8 (9) × 3–3.5 μm (n = 40, lm = 7.6 μm, wm = 3.07 μm, Q = 2.14–2.67, q = 2.48), cylindrical, smooth, hyaline, thin-walled. Basidia (16) 20–25 × 5.5–7 μm, clavate or elongated, bearing four sterigmata. Lamella-edge sterile, with short cheilocystidia. Cheilocystidia crowded, (12) 14–19 × (5.5) 6–7 (8) μm, with median constriction, ellipsoid or utriform and apical protrusion, hyaline, thin-walled. Sclerocystidia abundant, (16.5) 19–24 × (5) 5.5–6.5 (7) μm, clavate to irregularly fusoid, with a thickened wall, hyaline. Hymenophoral trama irregular, radiate construction, hyaline, similar with context. Pileipellis epicutis, made up of thick-walled generative hyphae, 3–5 μm diameter, occasionally brunched, not inflated, light brown. Stipitipellis similar to pileipellis.

Ecology.

Solitary on rotten wood in broad-leaved forest.

Distribution.

China (Zhejiang Province).

Notes.

This species is characterised by the concentric darker zones pileus, decurrent lamellae with cross-veins, shorter stipe, longer basidiospores, diverse and shorter cheilocystidia and smaller sclerocystidia.

Panus baishanzuensis is close to P. similis and P. velutinus in morphology, because of the similar pileus and lamellae. However, the pileus of P. velutinus and P. similis without concentric darker zones distinguished them from P. baishanzuensis . Meanwhile, the stipe of P. baishanzuensis is extremely short, while the stipe of P. velutinus and P. similis is long and slender. In addition, the lamellae of P. baishanzuensis have cross-veins with six tiers of lamellulae, but P. velutinus and P. similis have no cross-veins and with three or four and five tiers of lamellulae. At the same time, P. velutinus and P. similis both have pseudosclerotia, while the pseudosclerotium of P. baishanzuensis is absent. Lastly and most importantly, P. baishanzuensis has longer basidiospores, graeter Q values, shorter cheilocystidia and smaller sclerocystidia than P. similis and P. velutinus .

Figures

Figure 4. Habitat of Panus baishanzuensis (FJAU 67794, holotype) A basidiocarp B pileus C lamellae D, E stipe. Scale bars: 1 cm.

Figure 5. Microscopic characteristics of Panus baishanzuensis (FJAU 67794, holotype) A basidia B basidiospores C sclerocystidia D cheilocystidia E pileipellis hyphae F generative hyphae of context G skeletal hyphae of context. Scale bars: 10 μm.