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

MycoBank number: MB 558179; Index Fungorum number: IF 558179; Facesoffungi number: FoF 10745; Fig.1

Etymology – The species epithet jawadhuvensis refers to the type locality of basidiomata collection.

Holotype – MUBL4011

Basidiocarps perennial, solitary, pileate, sessile, light in weight, hard when dry. Pileus dimidiate, convex to meagrely ungulate, with no distinct crust, projecting up to 5.7 cm, 9.5 cm wide and 3.4 cm thick near the base. Pilear surface velvety, light brown (6D6) to rust-brown (6E8) and meagerly warted when young, on maturity pilei becoming rough, weakly rimose, concentrically, narrowly sulcate, weakly zonate. Margin entire, round to obtuse, brown (6E4) to dark brown (6F5), velutinate when young, developing into brownish grey (6F2) to greyish brown (6E3), glabrous on maturity. Pore surface raw umber brown (5F8) to brown (6E7). Pores round to angular, regular, 4–8 per mm. Dissepiments entire, thick. Context up to 2.7 cm, homogeneous, yellowish-brown (5E8) to dark brown (6F7). Tubes yellowish-brown (5D8) to light brown (6D6), up to 0.7 cm thick, tube layers stratified, each stratum 0.2 to 0.4 cm with a thin layer of context in between.

Hyphal system – strictly dimitic, Generative hyphae dominant; both skeletal and generative hyphae acyanophilous; tissue darkening with KOH without swelling. Context Generative hyphae, thin to thick-walled, hyaline to yellow, simple septate, branched, 2–6.5 μm diam.; skeletal hyphae, thick-walled with narrow lumen, unbranched, yellowish-brown, aseptate, 2–5.7 μm diam. Trama Generative hyphae, thin to thick-walled, yellow to brown, septate, rarely branched, 2–5.2 μm dia.; skeletal hyphae, thick-walled with narrow to wide lumen, yellowish-brown, aseptate, unbranched, 2–5.2 μm dia. Setae, cystidioles absent. Basidioles dominant, clavate, 7.7–14×3.8–7.2 μm. Basidia clavate to broadly clavate, with four sterigmata, 8.5–15×5–8.5 μm. Basidiospores broadly ellipsoid to subglobose, thick-walled, smooth, yellow in water, turning rust-brown in KOH, (4.8–) 5.1–6.4 (–6.9)×(4.1–) 4.4–4.9 (–5.2) μm (n=50/2), Q =1.1–1.3, CB ̄, IKI ̄. Chlamydospores globose to subglobose, thick-walled rust brown to reddish-brown, 5.2 – 8.5 × 4.1–7 μm, CB ̄, IKI ̄.

Specimen examined – India, Tamil Nadu, Thiruvannamalai district, Jawadhu hills, Jamunamarathur, 12.64° 54′ 19.1″ N 79° 18′ 33″ E, on living angiosperm tree (Albizia amara (Roxb.) Boiv., Fabaceae), 09 February 2018, Kezhocuyi Kezo (MUBL4011, holotype).

GenBank numbers – MW040079 (ITS), MW048886 (LSU), MW690924 (tef1).

Notes – Fulvifomes jawadhuvensis shares similarities with F. grenadensis by having dimidiate to ungulate pileus, round to obtuse margin, absences of cystidioles, but the former lacks distinct crust after velvety pileus wears off and no. of pores per mm. Larger broadly ellipsoid to subglobose spores in F. jawadhuvensis differ from smaller spores in F. grenadensis (4–6×3–4 µm) (Ryvarden 2004). The new Indian species share other common characteristics with F. elaeodendri, F. hainanensis, F. thailandicus, in having dimidiate to ungulate basidiomata, zonate pileus with rimose patten (except F. hainanensis), pores per mm, distinctly thick-walled, colored basidiospores, absence of setae, but significantly varies basidiospores size and absences of cystidioles (Zhou 2014; Tchoumi et al. 2020). Fulvifomes jawadhuvensis and F. centroamericanus share only dimidiate pilei and absences of cystidioles and differ in other features; the former varies entirely from F. krugiodendrii (Ji et al. 2017). Fulvifomes jawadhuvensis shows variations with F. nonggangensis and F. tubogeneratus in basidiomata characters and microscopic illustrations (Zheng et al. 2021).

Figure 1 – Fulvifomes jawadhuvensis (MUBL4011, halotype). 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.