Hymenagaricus pakistanicus M.F. Syed

Syed, Mahrukh Farid, Saba, Malka, Chattha, Seratt Mukhtar & Hosen, Md. Iqbal, 2023, Hymenagaricus pakistanicus (Agaricaceae, Agaricales), a new species from Pakistan based on morphological and molecular evidence, Phytotaxa 594 (4), pp. 292-300 : 296

Hymenagaricus pakistanicus M.F. Syed & M. Saba, sp. nov. Figs. 3–5

MycoBank:—MB846346

Etymology:—“pakistanicus” refers to Pakistan, the country where the type was collected.

Diagnostic characters:— H. pakistanicus sp. nov. is distinguished from all other known taxa by a pileus with striate margin, and the absence of a membranous annulus.

Holotype:— PAKISTAN. Khyber Pakhtunkhwa province, district Karak, Tehsil Takht-e-Nasrati, Ziarat Siraj Khel , 70.40°– 71.30°N 32.48°– 33.23°E, elevation 556 m, gregarious on sandy clay soil, near Phoenix dactylifera L., Zizyphus spp (L.) Meikle, 28 August 2020, leg. M. F. Syed, coll. FAK195 ( ISL-F0010 ). GenBank ITS accession number OP082404 .

Description:— Basidiomata small to medium-sized. Pileus 2.4–3.0 cm in diameter, hemispherical to convex when young, plano-convex to applanate at maturity; white to pinkish white; central disk dark brown (7.5YR1/2#2B180E) with numerous small dark olive brown (2.5Y2/4#422D09) squamules on a light brown (5YR6/4#B78B78) background; margin striate, sometimes with floccose remnants ( Fig. 3A–E ). Lamellae free, dark reddish orange (7.5YR4/8#9E4540), regular, distant, with denticulate edge, intercalated with lamellulae, ( Fig. 3D ). Stipe 3–3.2 × 0.29–0.3 cm, central, cylindrical, with or without bulbous base, fistulose, equal, texture rough, reddish brown, sometimes covered with white fine squamules or fibrils. ( Fig. 3C–E ). Annulus absent. Context slightly reddening when cut or injured. Spore print dark brown. Smell indistinct. Taste unknown.

Basidiospores [60/3/4] (4.6–)4.9–6.2(–6.5) × (3.1–)3.3–4.9(–5.2) µm, Q = 1.13–1.80, Qav = 1.44, avl × avw = 5.7 × 3.9 μm, subglobose to broadly ellipsoid, smooth, thick-walled, yellowish brown to dark brown, apiculate, with central guttule ( Figs. 4A , 5A ). Basidia 15.6–24.1 × 5.2–10.4 µm, tetra-sterigmate ( Fig. 4C ), clavate, smoothwalled; sterigmata 2.6–2.8 µm long ( Fig. 5B ). Cheilocystidia 15.6–33.8 × 5.2–10.4 µm, clavate to narrowly clavate, sometimes cylindrical to broadly cylindrical, smooth, thin-walled ( Figs. 4D , 5C ). Pleurocystidia absent. Hymenophoral trama composed of regular to subregular hyaline hyphae, 2.6–7.8 µm wide ( Fig. 4C ). Pileal squamules composed of epithelial, hymeniform cells, thin-walled subglobose to irregular cells, encrusted with brownish pigments, 5.2–10.4 × 2–4 µm ( Figs. 4B , 5D ). Pileipellis a cutis of parallel, interwoven, loosely arranged, thin-walled hyphae, 4.6–10.4 µm diam, septate, hyaline, branched ( Fig. 5E ). Stipitipellis composed of hyphae 5.2–11.7 µm diam, regular, parallel, septate, hyaline, branched. Clamp connections absent ( Fig. 5F ).

Habit, habitat and distribution:—Caespitose, gregarious on sandy clay soil, saprotrophic, near Phoenix dactylifera and Zizyphus spp , collected from Tehsil Takht-e-Nasrati, Ziarat Siraj Khel, Karak, July and August. Currently only known from Khyber Pakhtunkhwa province in Pakistan.

Additional specimens examined:— PAKISTAN. Khyber Pakhtunkhwa province, district Karak, Tehsil Takht-e-Nasrati , 70.40°– 71.30°N 32.48°– 33.23°E, elev. 556 m, on ground, 24 July 2021, leg. M. F. Syed, coll. FAK196 ( ISL-F0011 ), GenBank accession number OP 082405 ; district Karak Tehsil Takht-e-Nasrati, 70.40°– 71.30°N 32.48°– 33.23°E, elev. 556 m, on ground 22 August 2021, leg. M. F. Syed, coll. FAK197 ( ISL-F0012 ), GenBank accession number OP082406 ; District Karak, Tehsil Takht-e-Nasrati , 70.40°– 71.30°N 32.48°– 33.23°E, elev. 556 m, on ground 28 July 2022, leg. M. F. Syed, coll. FAK198 ( ISL-F0013 ) .

Figures

FIGURE 3. A–E. Basidiomata of Hymenagaricus pakistanicus (Holotype) ISL-F0010 (OP082404). A–B. Basidiomata in the field. C–E. Gills and stipe view. Scale bars: 5mm. Photos by: Mahrukh Farid Syed

FIGURE 4. Hymenagaricus pakistanicus, microscopic characters (Holotype) ISL-F0010 (OP082404). A. Basidiospores, B. Squamules on pileus surface, C. Lamella trama with basidia, D. Cheilocystidia. Photos by: Seratt Mukhtar Chattha.

FIGURE 5. Line drawing of microscopic features of H. pakistanicus (Holotype) ISL-F0010 (OP082404). A. Basidiospores, B. Basidia, C. Cheilocystidia, D. Squamules on pileus surface, E. Pileipellis, F. Stipitipellis. Scale bars: 10µm. Drawings by: Seratt Mukhtar Chattha.