Russula ahmadii S. Jabeen, A. Razaq, A. R. Niazi, I. Ahmad & A. N. Khalid 2017, sp. nov.
Creators: name: Jabeen, Sana
name: Razaq, Abdul
name: Niazi, Abdul Rehman Khan
name: Ahmad, Ishtiaq
name: Grebenc, Tine
name: Khalid, Abdul Nasir
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Russulales
Russulaceae
Russula
Russula ahmadii

description: Russula ahmadii S. Jabeen, A. Razaq, A.R. Niazi, I. Ahmad & A.N. Khalid, sp. nov. (Figures 5–8)   
MycoBank number: MB 814605  
 Etymology:—The specific epithet “ ahmadii ” refers to S. Ahmad (Late), the pioneer Pakistani mycologist.   
Diagnosis:—Basidiomata small to medium, dark brown to greyish brown, tuberculate striate depressed pileus with some dark brown spots in the centre; white to cream, chambered stipe without any coloration and globose to subglobose amyloid basidiospores with ornamentation of verrucae with bifurcated apices and fine connectors forming partial reticulum.  
 Holotype:— PAKISTAN, Khyber Pakhtunkhwa province, Hazara division, Abbottabad district, Kuzah Gali, 2500 m asl, solitary on ground under Cedrus deodara, 21 September 2013, Sana Jabeen SJ9 (LAH35004!; GenBank for ITS: KT834638, for LSU: KX911834).   
 Pileus 1–4.5 cm broad, depressed at disc, dark brown (5YR1/2) at centre, sometimes in the form of dark brown spots, light brown (5YR5/4) to greyish brown (5YR5/2) towards margin, margins smooth and incurved when young becoming tuberculate-striate and uplifted at maturity; surface usually dry, sometimes slimy. Lamellae up to 2.5 mm broad, creamy white (2.5Y9/2), regular, adnexed, sub-distant to close; edges entire; lamellulae few. Stipe 2.5–3.5 cm × 0.7–1.0 cm, central, cylindrical, slightly narrower towards base, chambered; surface smooth, white to cream (2.5Y9/2) towards the apex and greyish brown (5YR5/2) sometimes in the form of patches towards the base. Spore print offwhite to cream.   
 Basidiospores [60/6/6] (5.6) 6.1–9.2 (9.4) × (5.4) 5.7–6.6 (7.5) μm, Q = (1.00) 1.03–1.28 (1.56), avQ = 1.18 ± 0.17, subglobose to broadly ellipsoid; ornamentation amyloid, made up of up to 0.3 μm high verrucae, apices bifurcated, or rounded in the form of short warts, sometimes forming a partial reticulum by the presence of fine connectors; apiculus prominent; guttulate, pale yellow in 5% KOH. Basidia (29) 29.7–38.9 (40.1) × (9.2) 9.4–11.3 (11.8) μm, clavate, pale yellow in 5% KOH, guttulate; clamp connections absent. Cheilocystidia (49.7) 52.6–57.3 (59.9) × (8.9) 9.9–10.8 (11.5) μm, fusiform, mucronate to rostrate, pale yellow in 5% KOH, guttulate. Pleurocystidia (64.7) 66.5–78.3 (80.7) × (7.5) 7.8–8.3 (9.0) μm, variable in shape, from fusiform, mucronate to rostrate, pale yellow in KOH, guttulate. Pileipellis cutis, hyphae (2.1) 3.3–4.2 (4.5) μm wide, filamentous, branched, pale yellow to hyaline in 5% KOH, septa infrequent. Pileocystidia (20.1) 24.3–30.4 (45.9) × (2.8) 3.6–4.8 (5.6) μm, fusiform to mucronate, clustered in the pileus centre, becoming sparse towards the margins. Stipitipelis cellular to filamentous, hyphae (1.4) 1.6–7.0 (8.0) μm wide, branched, with bifurcated ends, pale yellow to hyaline, rarely septate, clamp connections not observed.   
Habitat and distribution:—The species is found in coniferous forests of Pakistan ranging from moist temperate to dry temperate climate.  
 Additional specimens examined:– PAKISTAN. Khyber Pakhtunkhwa province, Hazara division, Abbottabad district, Ayubia-Khanspur (helipad forest), 2400–2580 m asl, solitary on ground under Abies pindrow (with C. deodara and Pinus spp. in vicinity), 18 August 2010, Abdul Razaq K13 (LAH18081013!; GenBank for ITS: KU535609); Ayubia National Park, 2400–2580 m asl, solitary on ground under A. pindrow (with C. deodara and Pinus spp. in vicinity), 21 August 2010, Abdul Razaq K6 (LAH2101006!; KU535608); Malakand division, Swat district, Kalam, 2060–2065 m asl, solitary on ground under C. deodara, 3 September 2013, Sana Jabeen SJ54 (LAH35005!; GenBank for ITS: KT834639); 4 September 2013, Sana Jabeen SJ74 (LAH35006!; GenBank for ITS: KT834640); Mashkun, 2500 m asl, solitary on ground under C. deodara, 5 September 2013, Sana Jabeen SJ48 (LAH35007!; GenBank for ITS: KT834641).   
 Description of ectomycorrhiza:— Ectomycorrhizal system dichotomously ramified to coralloid with a wooly appearance, up to 4 mm long, tips 0.5–2 mm long and up to 0.25 mm wide, apex 0.2 mm wide, base up to 0.25 mm wide; main axis 1 mm in diameter, light brown (10YR4/10) to dark brown (10YR3/8) or black at maturity; un ramified ends straight, cylindrical; mantle silvery white to pale yellow (10YR8/8), distinct, reflective, host tissue visible under the mantle. Rhizomorphs frequent, smooth, pale yellow (5YR7/10) to transparent. Emanating hyphae abundant branched, pale yellow (5YR7/10) to transparent. Mantle psedoparenchymatous in all layers, non-gelatinous, cells variable in shape. Inner mantle layer pseudoparenchymatous, cells angular to rounded, elongated or lobed, tending towards the plectenchymatous state (mantle type L) (Agerer 1987 –2006, Agerer & Rambold 1998), cells pale yellow to transparent, 10.7 ± 3.2 × 5 ± 0.6 μm, cell contents clear. Outer mantle layer pseudoparenchymatous, cells angular to rounded, elongated or lobed, tending towards the plectenchymatous state (mantle type L, Agerer 1987 – 2002, Agerer & Rambold 1998), cells pale yellow to transparent, 10.6 ± 4.1 × 5 ± 0.4 μm, matrix clear. Emanating hyphae straight, elongated, cylindrical, septate, clamped septa frequent, 2.2 μm in diameter, surface smooth, contents clear, ramification rather frequent, Y-shaped; hyphal endings simple to bifurcate, anastomosis not observed. Cystidia frequent, lageniform, up to 14.7 μm in length with strongly inflated base, up to 5.4 μm wide, a long straight neck up to 2.3 μm in diameter. Rhizomorphs frequent, hyphae branched, uniform and loosely arranged, intermingled, up to 2.7 μm in diameter, septate, clamp connections frequent, pale yellow to transparent.   
 Specimens examined:— PAKISTAN. Punjab province, Rawalpindi division and district, Patriata, 2300 m asl, associated with C. deodara, 21 September 2013, Sana Jabeen & Hassan Ayub SJ171 (LAH-EM3-2013!; GenBank for ITS: KT834642); SA158 (LAH-EM9-2013!; GenBank for ITS: KU535610); SA166 (LAH-EM10-2013!; GenBank for ITS: KU535612); SA110 (LAH-EM11-2013!; GenBank for ITS: KU535613); Malakand division, Swat district, Mashkun, 2500 m asl, associated with C. deodara, 5 September 2013, Sana Jabeen & Abdul Nasir Khalid SA48 (LAH-EM8-2013!; GenBank for ITS: KU535610).
description: Published as part of Jabeen, Sana, Razaq, Abdul, Niazi, Abdul Rehman Khan, Ahmad, Ishtiaq, Grebenc, Tine & Khalid, Abdul Nasir, 2017, Russula ahmadii (Basidiomycota, Russulales), a new species in section Ingratae and its ectomycorrhiza from coniferous forests of Pakistan, pp. 241-253 in Phytotaxa 321 (3) on pages 246-248, DOI: 10.11646/phytotaxa.321.3.2, http://zenodo.org/record/13697640