Agaricus karakensis T. Ullah

Ullah, Tauseef, Ullah, Khetab, Kamal, Asif & Saba, Malka, 2024, Agaricus karakensis sp. nov. (Agaricaceae, Agaricales), a new species from Pakistan, Phytotaxa 658 (2), pp. 191-202 : 196-200

Agaricus karakensis T. Ullah & M. Saba sp. nov. ( Figures 4A–F – 6A–F )

MycoBank: MB 844743

Etymology:—‘karakensis’ refers to the locality i.e. district Karak, where species was first time collected.

Diagnosis:—The peculiar features which differentiate the Pakistani collection from Agaricus bitorquis are; pale yellowish pink color basidioma, lack of fibrillose scale, semi-hypogeous nature, mild unpleasant smell, dark reddish brown lamellae, clavate shape stipe, amygdliform and apiculate basidiospores, globose to obovoid shaped Cheilocystidia and dump habitat.

Type:— PAKISTAN. Khyber Pakhtunkhwa Province: District Karak, N71º7ʹ67ʹʹ E32º9ʹ41ʹʹ, elev. 540 m, 22 July

2020, Tauseef Ullah (KTK07).

Description:—Medium size basidioma having a mild unpleasant smell, pileus 2–6 cm broad and 4–10 mm thick, slightly depressed, initially broadly convex but later on turn into a plan to subplane and flat at maturity, smooth surface, semi-hypogeous, pale yellowish pink (7.5YR 9/2 # FBDFD7) in color, no discoloration on touching or cutting, lack of fibrillose scale on surface, smooth and entire margin but become cracked at maturity. Lamellae 3–5 cm, free, crowded, first light reddish brown (2.5YR 6/4 #B9897D) in color and then become dark reddish brown (7.5R 1/2 #2E151A) at full maturity, intercalated and two tires of lamellulae. Stipe ranges from 3–5 cm long and 1 cm thick, smooth above the annulus, clavate shaped, cylindrical, woody, solid central, off-white while at maturity stipe becomes blackish at the top because of spore black color, dusty base while tapering upward. Annulus 5–7 mm broad, persistent, membranous, and hinging downward, initially pendant type but reduce afterward.

Basidiospores 7.2–10 × 5.5–7.5 μm, amygdliform but rarely subspherical, solid, smooth and thick-walled, non-amyloid, prominent apiculate, monoguttulate, rarely diguttulate, oil globule in circular form, light brown to dark brown coloration in KOH. Basidia 26.2–34.1 × 11.2–14.1 μm, light brown coloration, two or four sharped sterigmata, (2.5–4.3 μm), nearly clavate to sub–clavate shaped, thin-walled, non-amyloid, one or two oil globules present in some basidia. Cheilocystidia 28.2–33.4 × 12.5–18.5 μm broad, globose to obovoid shaped, smooth and thick-walled, non-amyloid, oil globule absent, light brown color. Pileus material 8.2–25.4 μm, nonamyloid, smooth and thick-walled, angular, or irregularly shaped. Pileus and stipe hyphae ranging from 3.5–10.4 μm, cylindrical, distinctive broader at the internodal region, hyaline, irregular, septate, branched, clamp connection absent.

Habit and habitat:—This species was collected from tropical habitat during the monsoon season (July–September) from the dump soil and at the base of boundary wall.

Distribution:—Only known from Pakistan, Khyber Pakhtunkhwa.

Edibility:—Unknown.

Other collections:— PAKISTAN. Khyber Pakhtunkhwa Province: District Karak, N71º7ʹ67ʹʹ E32º9ʹ41ʹʹ, elev. 540 m, 12 August 2021, Tauseef Ullah (KTK08).

Figures

FIGURE 4. A–F. Macro-morphological characterization of Agaricus karakensis T.Ullah & M.Saba sp. nov. Photos shoot at their natural ecological habitat. Scale bar: A–B = 5 mm. Photos by Tauseef Ullah.

FIGURE 6A–F. Micro–morphological characterizations of Agaricus karakensis T.Ullah & M.Saba sp. nov.A. Basidiospores, B. Basidia, C. Cheilocystidia, D. Pileus material, E. Pileus hyphae, F. Stipe Hyphae Scale bar = 10µm.