Candolleomyces denticulatus M. Khalid, Haqnawaz & Afshan, 2025

Candolleomyces denticulatus M. Khalid, Haqnawaz & Afshan sp. nov.

Figs 5 View Figure 5 , 6 View Figure 6

Etymology.

The species name “ denticulatus ” (Latin) refers to the toothed cap margins.

Holotype.

Pakistan • Punjab Province: Lahore District, University of the Punjab , ( 31°29'39"N, 74°18'06"E, 227 m a. s. l.), on loamy soil, rich in organic matter, under Punica granatum Linn , 15 Aug. 2024, Muhammadah Khalid, Abdul Nasir Khalid, and Muhammad Haqnawaz, PU–10 ( LAH 38584 About LAH ). GenBank: PV 265175 [ ITS], PV 265186 [ LSU], PV 357395 [ tef -1α]. GoogleMaps

Diagnosis.

Candolleomyces denticulatus differs from C. rubrobruneus in having toothed cap margins, abundant squamules when young, a grayish-white pileus with a pale orange center, grayish-white edges of the lamellae, and cheilocystidia that are globose, ellipsoid, pedunculate, globose, oblong, or lecythiform; at the same time, caulocystidia are tibiiform, lecythiform, oblong, fusiform, and moniliform.

Description.

Pileus 20–40 mm diam., parabolic in young stages, convex to plane when old, veil remnants present, dense squamules present in young stages, mostly removed when old, margin straight and split in symmetry to toothed, cracked surface, light gray (10 YR 8 / 1) to grayish white (N 8 / 0) with dull reddish brown (10 YR 5 / 4) to pale orange (5 YR 8 / 3) center, grayish white (N 8 / 0) squamules. Lamellae adnate, narrow, even to rarely eroded, with 3–7 tiers of lamellulae, forked, grayish brown (5 YR 6 / 2) to light brownish gray (5 YR 7 / 2), edge grayish white (N 8 / 0). Stipe 20–30 mm, central, equal, flexuous, surface scabrous, dull reddish brown (10 YR 5 / 4) to grayish white (N 8 / 0). Annulus absent.

Basidiospores [150 / 3 / 2], (6.0 –) 6.5–11.0 (– 11.6) × (4.2 –) 4.5–6.0 (– 6.3) µm, Q = 1.2–1.7, Qav = 1.56, amygdaliform in side view, ellipsoid in frontal view, smooth, guttulate, thick-walled, light red in water. Basidia (11 –) 11.9–21.1 (– 21.5) × (7.5 –) 7.9–9.1 (– 9.2) µm, clavate, hyaline to light gray (5 Y 7 / 1) in 5 % KOH, thin-walled, smooth, with 2–4 sterigmata, basal clamp connections present. Cheilocystidia 25–42 × 8–20 µm, narrowly utriform to broadly utriform, pedunculate, ovoid to conical, globose to subglobose, lecythiform, ellipsoid – pedunculate, narrowly lageniform, thick-walled, hyaline to yellowish gray (2.5 Y 5 / 1) in 5 % KOH. Pleurocystidia absent. Pileipellis an epitheloid hymeniderm, thick – walled, cells abundantly globose to subglobose, clavate to broadly clavate, ellipsoid to broadly ellipsoid, rarely utriform, oblong, lecythiform, cylindrical, 20–55 × 15–45 µm, hyaline to light gray (5 Y 7 / 1) in 5 % KOH. Stipitipellis made of 4.3–5.4 μm diam., subregular hyphae, rarely branched, hyaline in 5 % KOH, thin-walled septate, clamp connections abundant. Caulocystidia 27–64 × 8–18 µm, utriform to utriform pedunculate, slightly cylindrical, flexuous, ellipsoid, tibiiform, lecythiform, oblong, capitate, fusiform, moniliform, hyaline to light gray (5 Y 7 / 1) in 5 % KOH, thick-walled.

Ecology and habitat.

Gregarious and caespitose, terrestrial, on alluvial soil rich in organic matter.

Additional material examined.

Pakistan • Punjab Province: Kot Addu, Pirhar Gherbi ( 30°33'07"N, 70°50'40"E, 137 m a. s. l.), on loamy soil, 21 Aug. 2024, Muhammadah Khalid, Abdul Nasir Khalid, and Muhammad Haqnawaz, KA–103 ( LAH 38585 About LAH ). GenBank: PV 265176 [ ITS], PV 265187 [ LSU], PV 357396 [ tef -1α] GoogleMaps .

Notes.

Phylogenetically, Candolleomyces rubrobrunneus , C. pabbiensis , and C. kanhattiensis nov. sp. formed a separate branch from the new taxon C. denticulatus . Morpho-anatomically, Candolleomyces denticulatus is different from C. rubrobrunneus by having a toothed pileus margin, abundant squamules at the immature stage, grayish white pileus with pale orange center, grayish white edges of lamellae, yellowish gray basidiospores, ellipsoid pedunculate, utriform, oblong, lecythiform, cylindrical cheilocystidia; tibiiform, lecytheform, fusiform, moniliform caulocystidia. In contrast, C. rubrobrunneus has a straight margin, a dark brown pileus with a brownish, pale, fibrillose to floccose veil, grayish-orange to brown edges of lamellae, olive-brown basidiospores, broadly fusiform capitate cheilocystidia, and subcapitate apex of caulocystidia ( Nayana and Pradeep 2024). However, C. pabbiensis is distinguished from our new taxon by conical to broadly parabolic pileus with straight margins, grayish white lamellae, light brown basidiospores, and plump cheilocystidia with an obtuse to subobtuse apex ( Haqnawaz et al. 2024 b). Candolleomyces kanhattiensis differs from the new taxon C. denticulatus by having a sub-globose to campanulate pileus with decurved, undulating margins, a shiny stipe with a clavate base, greenish gray basidiospores, and cylindrical, ellipsoid, and globose cheilocystidia (in this study).