Fulvifomes malaiyanurensis Gunaseelan, S., Kezo, K. & Kaliyaperumal, M., sp. nov.

MycoBank number: MB 821517; Index Fungorum number: IF 821517; Facesoffungi number: FoF 10744; Fig. 1

Etymology – The species epithet “malaiyanurensis” referring to the locality of basidiomata collection.

Holotype – CAL 1618

Basidiocarps perennial, solitary, sessile, broadly attached to substrate, hard, light when dry. Pilei dimidiate, ungulate to triquetrous, projecting up to 5 cm, 12 cm wide and 4 cm thickness near the attachment. Pilear surface velutinate towards the margin, partially, concentrically zonate, brown (6E6) to greyish brown (6F3), cracked during collection. Margin obtuse often round, velvety shining, brown (5E8) to yellowish brown (5E4). Pore surface umber-brown (5E8). Pores regular, circular to angular, 5–7 per mm. Dissepiments thick, entire. Context yellowish-brown (5C7) to dark golden brown (5C7), woody corky, up to 2 cm thick. Tube layer brown (6D7), up to 2 cm long in distinctly stratified, individual layer up to 0.5 cm in length.

Hyphal system strictly dimitic, skeletal and generative hyphae acyanophilous, tissue darkening with KOH without swelling. Context: Hyphal system subparallel, generative hyphae dominant hyaline to yellow, simple septate, thin to thick-walled, 2.2–6.4 μm in diam, rarely septate and branched, skeletal hyphae rare, yellow to brown, thick-walled, with a narrow to wide lumen, infrequently septate, unbranched, 1.8–5.2 μm in dia. Trama Hyphae interwoven, color not distinct from context; generative hyphae thin to thick-walled, frequently septate 2–5.2 μm wide, skeletal hyphae thick-walled, unbranched, aseptate with narrow to wide lumen 2.7–5.2 μm. Hymenial setae, cystidia and cystidioles absent. Basidioles clavate, 5–16×3–7 μm. Basidia broadly clavate, with four sterigmata, 7–16×5–8 μm. Basidispores broadly ellipsoid to subglobose, smooth, yellow to golden yellow in water, turning golden brown to rustbrown in KOH, thick-walled, (4.2–) 4.6–5.4 (–5.7)×(3.9–) 4.2 – 4.9 (–5.2) μm, Q=1.09, (n=50/2), Q=1.05–1.25, CB ̄, IKI ̄. Chlamydospores globose to subglobose, thick-walled, rust-brown to reddish-brown, 5.7– 12.8×5.2–11.6 μm, CB ̄, IKI ̄.

Material examined – India, Tamil Nadu, Vizhupuram district, Malaiyanur, 37° 25′ 19.1″ N 23° 36′ 33″ W, on living angiosperm tree (Tamarindus indica L., Fabaceae), 25 October 2016, Sugantha Gunaseelan, MLCASB020, holotype. Additional specimen examined: India, Tamil Nadu, Vizhupuram district, Malaiyanur, 37° 25′19.1″ N 23° 36′33″ W, on living angiosperm tree (Tamarindus indica, Fabaceae), 25 October 2016, Sugantha Gunaseelan, (MLCASB021, Isotype).

GenBank numbers – MLCASB020-MF155651 (ITS), MF155652 (LSU). MLCASB021- MW048883 (LSU), MW690925 (tef1).

Notes – Fulvifomes malaiyanurensis is similar to F. thailandicus (Zhou 2015) in sharing yellowish-brown, broadly attached basidiomata, pore, dimitic hyphal and absence of cystidioles. However, F. malaiyanurensis is distinct by having ungulate to triquetrous, yellowish-brown, velutinate basidiocarp, acyanophilic subglobose basidiospores, lacking cystidioles. Fulvifomes malaiyanurensis differs from F. grenadensis (Ryvarden 2004), F. hainanensis (Zhou 2014) and F. imbricatus (Zhou 2015) in pileus character, pore per mm, shape and size of basidiospore. F. malaiyanurensis share a similar pileial character with F. robinae (Salvador-Montoya et al. 2018) but differs in hyphal system and basidiospore but shares pores/mm. Fulvifomes malaiyanurensis shares similarities with F. elaeodendri and F. yoroui in triquetrous up to ungulate basidiomata and pores per mm (Tchoumi et al. 2020; Olou et al. 2019) and differs in other characters. Macroscopically, F. malaiyanurensis may resemble African (Tchoumi et al. 2020), Asian (Zhou 2014, 2015; Liu et al. 2020; Du et al. 2021) and American (Ji et al. 2017) known species but shows variation in other taxonomic characters.

Figure 1 – Fulvifomes malaiyanurensis(CAL 1618, h0lotype). a – b Basidiocarp. c Stratified tube layer. d Tramal hyphae. e Context hyphae. f Basidioles. g Basidia. h Basidiospore. i Basidiospore in H2O. j Basidiospore in KOH. k Basidiospore in cotton blue. Scale: a = 3 cm.  c = 1 cm. d–k = 10 µm.