Rhodocybe pakistanica, Abdul & Khalid, 2024

Abdul, Zaman Khan & Khalid, Abdul Nasir, 2024, Molecular phylogeny and morphology reveal a new species of genus Rhodocybe sensu stricto Maire (Entolomataceae; Agaricales) from Pakistan, Cryptogamie, Mycologie 20 (10), pp. 127-137 : 129-131

Rhodocybe pakistanica sp. nov.

( Figs 3-5 )

The species is mainly characterized by centrally depressed and dull reddish brown or dull orange pileus with bright patches, light yellow to orange lamellae, light reddish gray and fibrillose stipe, ovoid or oblong basidiospores, lanceolate, subulate or ventricose-rostrate cheilo and pleurocystidia, and presence of gloeoplerous hyphae in pileal and hymenial trama.

TYPE MATERIAL. — Pakistan • Punjab Province, District Khushab, Noorpur Thal, Peelowains , on moist sandy soil with litter; 32°01’22.4”N, 71°59’32.4”E; 191 m a.s.l.; 01.VIII.2022; Zaman Khan & Junaid Khan P-154; holotype: LAH37947 ; GenBank: OR606543 (ITS), OR606541 (28S) .

ADDITIONAL MATERIAL EXAMINED. — Pakistan • Punjab Province, District Khushab, Noorpur Thal, Peelowains , on moist sandy soil near Ziziphus nummularia (Burm.f.) Wight & Arn. ; 31°59’17.36”N, 71°59’25.86”E; 191 m a.s.l.; 30.VII.2022; Zaman Khan & Junaid Khan P-146; LAH37948 ; GenBank: OR606544 (ITS), OR606542 (28S) • ibid.; 02.VIII.2022; Zaman Khan & Junaid Khan P-171; LAH37949 ; GenBank: OR606545 (ITS) .

ETYMOLOGY. — The specific epithet ‘pakistanica’ refers to the type locality of species.

HABIT, HABITAT, AND DISTRIBUTION. — Saprotrophic, solitary, terrestrial, on moist, sandy soil with litter in forest, near Dalbergia sissoo , and Ziziphus nummularia . Presently only known from Punjab, Pakistan.

MYCOBANK. — MB850258.

DESCRIPTION

Basidiomata

18-30 mm in length, small-sized. Pileus 7-28 mm diam., surface dull reddish brown (5YR 4/4, 5/4), at center becoming dull orange (7.5YR 6/4) or pale (5YR 8/3) towards periphery, with bright patches (7.5YR 5/6) scattering towards margins when mature, initially convex or hemispherical, depressed at center, becoming applanate or planoconvex and slightly depressed with age, margins decurved or plane at initial stage, uplifted or flaring upon maturity, undulate, entire.

Lamellae

Light yellow (10YR 8/3) to orange (10YR 8/4) or light (5YR 8/1) to gray (5YR 8/2), subdecurrent to decurrent, arcuate, broad or ventricose, brittle, entire or undate margins, lamellulae present in four tiers.

Stipe

15-28 × 2-4 mm, central, cylindrical or slightly tapering downwards, dull (2.5YR 6/3) to pale reddish (2.5 YR 7/3) or light reddish gray (7.5R 7/1) to grayish red (7.5R 6/2), with whitish fibrils on the surface, with rhizomorphs and whitish mycelial threads.

Context

Solid, pale reddish. Odor and taste not recorded.

Basidiospores

[50/3/3], 5.3-7×3.8-4.6 µm, avl×avw=5.9×4.2 µm, Q=1.35- 1.52, avQ=1.42, ovoid or oblong, sometimes ellipsoid, slightly undulate-pustulate, cyanophilic, inamyloid, non-dextrinoid, with prominent apiculus.

Basidia

21-26 ×6-8 µm, narrowly clavate to clavate, cyanophilic, with refractive contents in 5% KOH, thin-walled, two to four spored, sterigmata up to 4.4 µm in length.

0.07

Cheilo- and pleurocystidia

Rarely present, 24-37 × 4-7 µm, lanceolate, subulate, ventricose-rostrate, sometimes fusiform, cylindrical or clavate, with golden ochre or pale yellowish refractive contents in 5% KOH.

Lamellar trama

Consisting of 5.5-12.5 µm broad, regular, cylindrical, interwoven hyphae, hyaline in 5% KOH.

Gloeoplerous hyphae in hymenial and pileal trama

3.2-7.7 µm broad, cylindrical, elongated, with narrow endings, incrusted, golden refringent in 5% KOH.

Pileipellis

A cutis, consisting of 2.4-6.7 µm broad, cylindrical or elongate, thin-walled hyphae, brownish in 5% KOH.

Stipitipellis

A cutis, consisting of 3.2-8.8 µm broad, cylindrical, parallel, rarely branched hyphae, with clavate or narrowly fusiform ending elements, hyaline in 5% KOH.

Caulocystidia

Absent.

Clamp connections

Absent in all tissues.

Figures

FIG. 3. — Basidiomata of Rhodocybe pakistanica sp. nov.: A-C, LAH37948; D-F, LAH37947. Scale bars: 15 mm.

FIG. 4. — Microscopic characters of Rhodocybe pakistanica sp. nov. (LAH37947): A, basidiospores; B, basidia; C, D, cheilo- pleurocystidia; E, gloeoplerous hyphae in hymenial and pileal trama; F, stipitipellis. Scale bars: A, 8 μm; B, C, 10 μm; D, 16 μm; E, 20 μm; F, 25 μm.

FIG. 5. — Line drawings of Rhodocybe pakistanica sp.nov.(LAH37947):A, basidiospores;B, basidia;C, cheilo- pleurocystidia;D, gloeoplerous hyphae in hymenial and pileal trama; E, pileipellis; F, stipitipellis. Scale bars: A, 6 μm; B, C, 10 μm; D, 20 μm; E, 12 μm; F, 25 μm.