Bjerkandera lecomtei Tomšovský, V. Sabet, Welti, P.-A. Moreau & Dumez, 2025

Tomšovský, Michal, Sabet, Victor, Welti, Stéphane, Moreau, Pierre-Arthur & Dumez, Sylvain, 2025, A new species of Bjerkandera (Polyporales, Basidiomycota) from Europe, Phytotaxa 701 (1), pp. 95-104 : 99-101

Bjerkandera lecomtei Tomšovský, V. Sabet, Welti, P.-A. Moreau & Dumez , sp. nov.

MycoBank:—857869, Index Fungorum number:—IF901612; Figs. 3 , 4 , 5

Etymology:— lecomtei , dedicated to the Belgian mycologist Marcel Lecomte for generously shearing his broad experience in microscopy and field mycology.

Diagnosis:—Differs from temperate Bjerkandera spp. by resupinate basidiomes and absence of differentiated hypophyllum (“black line”). Similar Bjerkandera carnegieae and B. resupinata have different basidiospores and DNA sequences of ITS and LSU regions of ribosomal RNA gene.

Holotype:— Czechia, Bulhary , dead arm of river, alluvial forest NE of the village, 12 km BW of Břeclav, Acer campestre — on fallen trunk, coordinates approximately 48.8348564N, 16.7571736E, elevation 170 m, 04 May 1993, Petr Vampola ( P. Vampola 134/93), holotype MJ 2889 , isotype BRNM 844459 .

Basidiomata annual, resupinate, adnate, corky, occasionally up to 1 m broad, with a width between 30 and 50 cm., 0.5 mm thick at base. Pore surface whitish when fresh then yellow ochre to yellowish brown or brownish (5 C6 , 5 C 7, 5E 8), deep brownish when dry, sterile margin thin pale white to cream (4 A3 ), slightly fimbriate (or tomentose) ; pores mostly angular, sometimes rounded, 1–4 (5) per mm; dissepiments thin, entire to lacerated. Subiculum pale cream (4 A3 ) ; up to 0.2 mm thick with a distinct hymenopodial zone between subiculum and tubes in the type collection, not distinct in French (indoor) collections. Tubes up to 3 mm long, concolorous with the pore surface (5 C6 , 5 C7 ), becoming dark in KOH .

Basidiospores on holotype, n = 35 (5.5–)5.7–6.8–8(–8.3) × (3.4–)3.5–3.8–4.2(–4.9) μm, Q = (1.49–)1.56–1.81– 2.03(–2.14); on V. Sabet 2464, n =35) (4.9–)5.5–6.1–6.7(–7.2) × (2.9–)3.2–3.5–3.9(–4.0) µm, Q = (1.4–) 1.6–1.7– 2.0(–2.1); average values of both specimens L = 6.46 μm, W = 3.66 μm, Q = 1.76; ellipsoid or cylindro-ellipsoid, some slightly allantoid, thin-walled; negative in Melzerˈs reagent. Basidia 14.4–21.5 × 4.6–6.5μm, clavate, 4-spored; basidioles similar, 3.3–5.1 μm wide. Cystidia and cystidioles absent. Hyphal system monomitic, generative hyphae with clamp connections, smooth, colourless; hyphae of subiculum thick-walled with a wide lumen, rarely branched, 3.5–4.9 μm in diam; hyphae of tubes thin- to slightly thick-walled, frequently branched, 2.3–3.6 μm in diam.

The French material is somewhat distinct from the description of the Czech collection in its subiculum, which is approximately 300 µm thick and characterized by an alternation of compact zones composed of fascicles of unbranched, either horizontally or vertically oriented hyphae (3–8 µm wide) with moderately thickened walls (0.3–1 µm thick, locally yellowish in KOH), and looser zones predominantly composed of thin- to thick-walled, frequently branched and lobate, interwoven hyphae (2–4 µm wide). The tramal hyphal system is mainly composed of fascicles of unbranched, vertically oriented hyphae thinner (<4 µm) and shorter hyphae, thin or thick-walled, often highly and shortly branched, together forming a compact and cohesive structure overall.

Material examined: CZECHIA. South Moravian Region, Bulhary, dead arm of river, alluvial forest NE of the village, 10 km BW of Břeclav , Acer campestre —on fallen trunk, coordinates approximately 48.8348564N, 16.7571736E, 170 m a.s.l., 04 May 1993, Petr Vampola ( P. Vampola 134/93), holotype MJ 2889 , isotype BRNM 844459 ; PP104713

(ITS), PP104712 ( LSU). FRANCE. Loiret , Jargeau, on a house beam ( Quercus sp ), Nov 2024, Pierre-Yves Sachot ( V. Sabet, 2280, LIP) ; GenBank: PV226174 ( ITS), PV226177 ( LSU). Same locality, 12 Dec 2024, Pierre-Yves Sachot ( V. Sabet, 2464, LIP) ; Genbank : PV226175 ( ITS). Meurthe-et-Moselle, Jarville-la-Malgrange, on a house beam, 24 January 2025 ( V. Sabet, 2686, LIP) ; Genbank: PV226176 (ITS).

Notes: Bjerkandera lecomtei is similar to Raduliporus aneirinus ( Ceriporiopsis aneirina ). The two species differ in size of basidia and DNA sequences, while the dimensions of basidiospores and pores overlap. Other similar polypore occurring in the same habitat is Pouzaroporia subrufa having distinctly dimitic hyphal system. The color of B. lecomtei basidiomes is close to that of B. carnegieae but the species differ in ecology and basidiospore dimensions. The description of B. lecomtei is based one old herbarium specimen (collected in 1993 in nature) and three recent indoor collections in France. No fresh basidiome of the species was found recently in the type locality.

Figures

FIGURE 3. Basidiomata of Bjerkandera lecomtei BRNM 844459. a General view of basidiome. b Subiculum and tubes. c Tubes.

FIGURE 4. Microscopic structures of Bjerkandera lecomtei (MJ 2889, holotype). a Hymenium. b Basidiospores. c Generative hyphae. Scale bars: a–c = 5 μm.

FIGURE 5. Microscopic structures of Bjerkandera lecomtei (V. Sabet 2464). a–b Hymenium; c Basidiospore under scanning electron microscope, bar = 1 µm; d Hymenium under scanning electron microscope, bar = 10 µm.