Russula quercicola Razzaq, Shahid, Naseer & Khalid, 2023

Razzaq, Annum, Naseer, Arooj, Shahid, Soumia & Khalid, Abdul Nasir, 2023, Morphoanatomical and molecular characterization of two new Russula species in Section Ingratae from Pakistan, Phytotaxa 592 (1), pp. 21-38 : 28-31

Russula quercicola Razzaq, Shahid, Naseer & Khalid , sp. nov. ( Figures. 5–6 )

MycoBank:— MB841966

Diagnosis:— Russula quercicola is characterized by brown, smaller (3.9‒9 cm) pileus with incurved incised margins; globose and amyloid basidiospores (7.1‒12.4×5.5‒10.3 µm) with partially reticulated warts fused in long chains and prominent line connections.

Holotype:— Pakistan, Punjab, Rawalpindi, Bhurban , 33.9554° N, 73.4519° E, elev. 1828 m, on soil under Quercus , solitary, 07 September 2020, Annum Razzaq GC05 ( LAH36992 , GenBank accession number for ITS: MZ342769 , GenBank accession number for LSU: MZ342775 ).

Etymology:— ‘quercicola’ refers to the name of the Quercus forest from where it was collected.

Description: —Basidiomata small to med sized. Pileus 3.9–8.0 cm diameter, spherical to hemispherical and convex when immature becoming concave or depressed to infundibuliform with incurved margins at maturity, margins entire but eroded or cracked in mature fruiting body, cuticle matt and dull when dry but slightly viscid when humid, becoming wrinkled in older basidiomata, peeling to one third of the radius; prominent radial striations with smooth central disc, light brown (7.9YR 5.6/5.6) basal color with dark brown (7.9YR 5.6/5.6) patches at margins and central disc young fruiting body, becoming orange-brown with dark brown (7.9YR 5.6/5.6) patches to completely dark brown (0.4YR 3.5/5.3) with lighter central disc in mature basidiomata. Lamellae well developed, creamy white to off-white with brown spots (6YR 7.2/3.6) in mature ones, adnexed to narrowly adnate, crowded, lamellulae absent, subventricose to ventricose, margins even, entire becoming flexuous towards pileus periphery and concolorous. Stipe 3–6× 1.3–2 cm, equal to clavate in immature and young fruiting bodies while tapering upward in mature ones, central, longitudinally striated, light brown to dark brown (5YR 3.6/5.9) patches on entire surface in some fruiting bodies, off-white at base, Context moderately thick in pileus, hollow in stipe. Odor unspecific. Taste not recorded. Spore print not recorded.

Basidiospores (7.0‒)7.2‒8.9‒11.1(‒12.4) × (5.5‒)5.8‒7.9‒9.2(‒10.3) µm, Q = 1.07‒1.13‒1.28 globose to subglobose, partial reticulum, moderately distant to dense [(5–)6–7(–8) in a 3 µm diam. circle], often fused in long chains, connected by short and thick line connections, prominent hilar appendix, 1.06–1.86 µm, guttulated, amyloid. Basidia 41.3‒ 68.7×11.121.6 µm, 4-spored, sterigmata avl =4.1‒8.3 µm, broadly clavate, content present. Basidiole 20.6–33.8×7.4– 13.2 µm, clavate. Pleurocystidia 67‒145.5×6.3‒17.6 µm, clavate to fusiform, similar to cystidia on edge but relatively larger, without appendicule, granular contents. Cheilocystidia 44.9‒120.9×6.9‒16.3 µm, abundant, fusoid to clavate, apically acute to obtuse, mucronate 2.3–3.4 µm long apical appendage, hyaline in KOH, thin to moderately thick walled, granular contents. Marginal cells smaller, subcylindrical measuring 12.2–25.8×4.43–9.9 µm, apically obtuse. Hymenophoral trama composed of numerous sphaerocytes measuring 19.4–34.1×15.3–30.9 µm. Pileipellis hyphae 2.9–7.8 µm wide, filamentous, branched, frequently septate, thin. Hyphal terminations near the pileus margin thin walled, cylindrical and long apically obtuse terminal cells 14.1–46.5× 3.4–6.9 μm. Hyphal terminations near the pileus center intricate cylindrical and apically obtuse to sub-acute terminal cells 15–39×2.3–4.9 μm. Pileocystidia near pileus margins frequent, 70.1‒94.4×3.2‒5.7) µm, multi-celled, cylindrical to moniliform, branched, dense content. Pileocystidia near pileus center 53.8‒169.9×3.9‒8.5 µm, branched, multi-celled, apically constricted, thin walled, granular contents present. Clamp connections absent in all tissues.

Additional material examined:— Pakistan, Punjab, Rawalpindi, Bhurban , 33.9554° N, 73.4519° E, elev. 1828 m, on soil under Quercus , 04 September, 2020, Annum Razzaq GC07 ( LAH36993 !, GenBank accession number for ITS: MZ342770 ) . Annum Razzaq GB55 ( LAH36994 !, GenBank accession number for ITS: MZ342771 , GenBank accession number for LSU: MZ342774 ) . Khyber Pakhtunkhwa province, Parachinar , 33.5358° N, 70.0600° E, elev. 1,705 m, 21 September, 2020, gregarious on forest floor, Arooj Naseer PC29 ( LAH36995 !, GenBank accession number for ITS: MZ340578 ) . Arooj Naseer PC14 ( LAH36996 !, GenBank accession number for ITS: MZ340579 ) .

Figures

FIGURE 5. SEM micrographs. A‒B: Russula bhurbanensis (Holotype LAH36938). C‒D Russula quercicola (Holotype LAH36992).

FIGURE 6. Macromorphological characteristics of Russula quercicola A–B = GC05 (Holotype LAH36992), C= GB55 (LAH36994), D = GC07 (LAH36993).