Pseudofomitopsis fusca R.Saha, A.K.Dutta & K.Acharya, 2024

Saha, Rituparna, Dutta, Arun Kumar, Roy, Anirban & Acharya, Krishnendu, 2024, Two new polyporoid species of Fomitopsidaceae (Polyporales, Basidiomycota) from India, European Journal of Taxonomy 935, pp. 122-136 : 128-129

Pseudofomitopsis fusca R.Saha, A.K.Dutta & K.Acharya sp. nov.

MycoBank: MB 848689

Figs 2–3

Diagnosis

Pseudofomitopsis fusca sp. nov. differs from Pseudofomitopsis microcarpa in having annual, pileate, glabrous, corky, straw yellow to honey yellow coloured, laterally stipitate to sub-stipitate basidiocarp, turning reddish brown to black towards base, 7–8 pores per mm, and cylindrical to oblong ellipsoid basidiospores that are non-reactive in cotton blue (CB).

Etymology

The epithet ‘fusca’ refers to the colour of the pileus upper surface.

Type material

Holotype INDIA – West Bengal • Jalpaiguri district, Samsing forest , near Gorumara National Park ; 26°84′82″ N, 88°60′22″ E; 102 m a.s.l.; 4 May 2018; R. Saha, J. Tamang & K. Acharya RJK –01/2021; on dead wood of an unidentified angiosperm; GenBank no.: OQ918741 (ITS); CUH [AM776].

Paratype INDIA – West Bengal • Jalpaiguri district, Samsing forest , near Gorumara National Park ; 26°84′82″ N, 88°60′22″ E; 914 m a.s.l.; 4 May 2018; R. Saha, J. Tamang & K. Acharya RJK –09/2021; on dead wood of an unidentified angiosperm; GenBank no.: OQ918742 (ITS); CUH [AM777].

Description

Basidiocarp pileate, perennial, triquetrous to ungulate, sessile, woody, hard, 20–35 mm wide, projecting 15–25 mm and 8–15 mm thick. Pileus upper surface applanate, shiny, glabrous, azonate, dark brown (9F4). Context 4–10 mm thick, brownish grey (7C2), woody, unchanged in KOH. Margin concolorous to the pileus upper surface, 0.8–1.5 mm thick. Pore surface yellowish grey (2C2), pores angular, 3–5 per mm. Tubes concolorous to the pore surface, 2–5 mm deep.

Hyphal system dimitic. Generative hyphae hyaline, thin-walled, branched, clamped, 1.65–3.5 µm wide. Skeletal hyphae thick-walled to solid, highly branched, hyaline, 1.5–5 µm wide. Basidia clavate, 4-sterigmate, hyaline, smooth, thin walled, 10–20 × 3.5–5.5 µm in diam. Cystidia absent. Cystidioles fusoid, thin-walled, hyaline, smooth, 9.5–16.5 × 3–3.5 µm in diam. Basidiospores thin-walled, hyaline, smooth, ellipsoid, aguttulate, reacting positive in cotton blue (CB), 3–3.7–5 × 1.5–2.9–3.5 µm in diam., Q = 1.09–1.99, Q m = 1.34.

Remarks

The new species is quite exceptional. Characteristic features of Pseudofomitopsis fusca sp. nov. are: perennial, triquetrous to ungulate, sessile (20–30 × 15–20 × 8–15 mm) basidiocarp with glabrous, dark brown upper surface; yellowish grey pore surface; dimitic type of hyphal system with clamped generative hyphae; fusoid cystidioles; ellipsoid, CB positive basidiospores measuring 3–5 × 1.5–3.5 µm with a mean Q value of 1.34.

Figures

Fig. 2. Field photographs of fresh basidiocarps of Pseudofomitopsis fusca R.Saha, A.K.Dutta & K.Acharya sp. nov. in natural habitat, collected from West Bengal, India (CUH [AM776], holotype). Scale bar = 10 mm. Photograph by R. Saha.

Fig. 3. Microscopic characteristics of Pseudofomitopsis fusca R.Saha, A.K.Dutta & K.Acharya sp. nov. (CUH [AM776], holotype). A. Basidia. B. Cystidioles. C. Generative hyphae. D. Skeletal hyphae. E. Basidiospores. Scale bars = 5 µm. Drawing by R. Saha.