Polyporales » Polyporaceae » Panus

Panus subfasciatus

Panus subfasciatus Thongbai, Karun., C. Richter & K.D. Hyde.

Index Fungorum number: IF 552827; Facesoffungi number: FoF02915


Basidiomata (Fig. 2) small-sized, often short and stocky, 1.2–2.5 × 0.5–1.0 cm in diameter, cylindric, brownish violet to purple-brown (11D5–6) when young, greyish ruby to ruby (12D7–8) when old, leathery, solid, dry; surface concolorous with the pileus, velutinate, fully covered with short and soft hairs, brownish grey (11C2); context white to pale purplish, consisting a dimitic hyphal system with skeletal hyphae. Pileus 2.5–5.5 cm in diameter, thin, slightly umbilicate centre, coriaceous, infundibuliform; surface brownish-grey to violet-brown (10E3–4), often purplish fuscous especially towards the margin, velutinate with numerous hispid squamules forming erect hairs or hispid-strigose; margin at first involute, then hispid. Lamellae 0.3 mm broad, with 3–5 tiers of lamellulae, deeply decurrent, purplish-black, moderately distant to moderately crowded.

Basidiospores (Fig. 2b–e) (5.03–)5.28–6.44(–6.56) × (3.04–)3.33–4.16(–4.44) μm (n = 40) Lm = 5.73 μm, Wm = 3.61 μm, Q = (1.34–)1.43–1.92(–1.95), Qm = 1.60 μm, ellipsoid to elongate, hyaline, thin-walled, with few contents. Basidia (Fig. 2f–i) 17–21 × 7–10 μm, clavate to elongate clavate, 4-spored or occasionally 2-spored, with sterigmata up to 6 μm long; clamps present at base of basidia. Lamella edge sterile with abundant cheilocystidia. Cheilocystidia (Fig. 2l) 24–28 × 15–25 μm, clavate, hyaline, thin-walled. Sclerocystidia abundant on the sides of the lamellae, 32–40(–55) × 6–9(–12) μm, initially clavate, thin-walled. Pileipellis an epicutis of impact, interwoven, slightly thick-walled; generative hyphae 2.4–5 μm wide, branching, with clamp connections. Generative hyphae (Fig. 2j) 2.5–3 μm, inflated, undifferentiated hyphae, hyaline, thin-walled, branching, with clamp connections. Skeletal hyphae (Fig. 2k) 2.5–3.5 μm, cylindrical, hyaline, slightly thick-walled.

Habitat: On dead and rotting wood in forest of Fagaceae.

Material examined: THAILAND, Chiang Rai Province, along the road number 1149, Mae Fah Luang Sub-District, Mae Fah Luang District, 17 June 2014, collector Benjarong Thongbai (MFLU 16-2129, holotype).

Notes: Panus subfasciatus is characterized by its brownish violet to purple brown young basidomata. Later they turn greyish ruby, leathery, solid, dry and are fully covered with short brownish grey hairs. In some aspects it bears a superficial resemblance to Panus fasciatus (Berk.) Singer and Lentinus concentricus Karunarathna, K.D. Hyde & Zhu L. Yang. Panus subfasciatus is easily distinguished from P. fasciatus with its ochraceous basidiomata and abundance of sclerocystidia, which are clavate or fusoid, 22–32 × 4–9 μm (Corner 1981; Pegler 1983). Panus subfasciatus differs from L. concentricus by the latter having yellowish brown-clay, velvety, concentrically zonate of basidiomata and absence of sclerocystidia (Karunarathna et al. 2011). Panus subfasciatus also bears a superficial resemblance to Panus conchatus (Bull.) Fr. which also has purplish brown basidiomata but is lacking cilia. The phylogenetic trees obtained from RAxML analyses are shown in Fig. 1. Panus subfasciatus was statistically supported in the Polyporaceae. In the major clade, P. subfasciatus clustered in a subclade that predominantly contained Panus species and Lentinus strigosus, while a second subclade exclusively contained Lentinus species. Panus subfasciatus appeared most similar to P. conchatus (unpublished according to the entry in GenBank) and a yet undescribed Panus species (BS = 82%). The phylogenetic tree suggests that the nrITS region may be useful for preliminary phylogenetic analyses, also because this is the most frequent DNA locus from which references are available. However, an expanded taxon sampling, best supported by a multi gene genealogy, should be carried out to redefine the boundaries between Lentinus and Panus. The new fungus was recently referred to as Lentinus cf. fasciatus in a report of a new secondary metabolite named lentinulactam (Helaly et al. 2016). Nevertheless, after the outcome of the phylogenetic study we preferred to place it in the genus Panus because it is appears closer to the type species of that genus, P. conchatus.



Fig. 1 Phylogenetic tree generated with RAxML (GRTGAMMA) based on ITS sequence data aligned with MAFFT. Bootstrap values higher than 70% are shown above or beneath the branches at nodes. The tree is rooted with Polyporus conifericola KU189783, Polyporus tubiformis AB587634 and Polyporus melanopus AF516569. Panus subfasciatus LT614958 (Ex-type) is highlighted in blue. GenBank accession numbers are provided after each species name.