Agaricus duplocingulatoides Tarafder, A.K. Dutta & K. Acharya, in Tarafder et al., Phytotaxa 374(2): 142 (2018)
Index Fungorum number: IF 826889; MycoBank number: MB 826889; Facesoffungi number: FoF 14217; Fig. 1
Holotype – CUH AM537
Macroscopic characters – Basidiomata medium. Pileus 47 mm diam., broadly convex with a low umbo; surface orange white (6A2) with brown (6E5) disc, which is smooth, with pale brown (6E5) appressed squamules, dry; margin straight, uneven, exceeding the lamellae. Lamellae free, dull red to maiden’s blush (8B3/8B4) up to 6 mm wide, crowded with lamellulae of 2–5 mm length; edge concolorous with the sides, entire. Stipe 55 ×6 mm, central, cylindric, hollow, tapering downward with a small bulbous base; surface orange white (5A2) with white pruinae, vanishing on handling and become brownish. Annulus superior, white, membranous, pendant, flaring with white floccose squamules on lower side, double edged, evanescent. Context white, up to 5 mm, thick, soft, fleshy. White mycelial codons present. Odor pleasant.
Microscopic characters – Basidiospores 6–6.8(8) × 4–4.8 μm diam. (avL = 6.24 ± 0.38 μm, avW = 4.18 ± 0.28), Q = 1.3–1.8 μm, (avQ = 1.45 ± 0.1), ellipsoid, smooth, brown, thick-walled. Basidia 18–28×6–8 μm, clavate, tetrasporic, thin-walled, hyaline. Lamellae edge sterile with crowded cheilocystidia. Cheilocystidia abundant, 12–30 × 6–22 μm, pyriform, clavate, broadly clavate, globose, vesiculose, thin-walled, hyaline. Pleurocystidia absent. Hymenophoral trama regular, 2.4–8 μm diam., composed of cylindrical to inflated hyphae, constricted at the septa, thin-walled, hyaline. Subhymenium pseudoparenchymatous. Pileal trama composed of multiseptate, cylindrical to inflated hyphae, 6.4–40 μm diam., thin-walled, hyaline. Pileipellis a cutis interrupted at places with bundles of hyphae, 3.2–7.2 μm wide with yellowish brown contents. Stipitipellis composed of parallel, multiseptate cylindrical hyphae, 4–15 μm wide, pale yellowish in KOH, thin-walled. Oleiferous hyphae present. Clamp connections absent.
Macrochemical reactions – Schäffer’s and KOH reactions negative.
Habitat and distribution – solitary on soil in grass land, known only from the type collection in West Bengal, India (Tarafder et al. 2018) and Kerala State, India.
Material examined – India, Kerala State, Thiruvananthapuram district, Palode, JNTBGRI campus (8.75° N, 77.02° E, elev. 150 m), soil in grass land, 24 July 2019, TBGT(M)17885.
GenBank number – ITS: OP503497.
Notes – Agaricus duplocingulatoides Tarafder, A.K. Dutta & K. Acharya was described from West Bengal, India (Tarafder et al. 2018). The species is characterized by a negative Schäffer’s test, presence of small brownish squamules on the pileus, fistulose stipe with rounded bulbous base, considerably shorter pileipellis hyphae, and presence of pyriform to broadly clavate cheilocystidia. Our collection is morphologically and molecularly similar to the holotype collection of A. duplocingulatoides however, our collection has larger basidiomata than the holotype collection (22–32 mm diam.). Therefore, we identified our collection as A. duplocingulatoides.
Figure 1 – Agaricus duplocingulatoides (TBGT17885). a Habit. b Gill view. c Sectional view. d Basidia. e Basidiospores. f Cheilocystidia. Scale bars: a–c=10 mm, d–f=10 μm