Trogia benghalensis K. Acharya & A.K. Dutta, 2017

Dutta, Arun Kumar, Nandi, Sudeshna, Tarafder, Entaj, Sikder, Rimpa, Roy, Anirban & Acharya, Krishnendu, 2017, Trogia benghalensis (Marasmiaceae, Basidiomycota), a new species from India, Phytotaxa 331 (2), pp. 273-280 : 275-278

Trogia benghalensis K. Acharya & A.K. Dutta , sp. nov., Figures 1 & 2

MycoBank MB 822864

Etymology:—The specific epithet ‘ benghalensis’ refers to West Bengal, India, the region where the type species was discovered.

Diagnosis:—Pileus small to medium sized (8–23 mm), greyish yellow to light orange; lamellae subdistant to moderately close; stipe central, greyish yellow to dull yellow; basidiospores 5–8 × 5–7.5 μm (Q mean of 1.1), globose to subglobose or broadly ellipsoid; basidia 2–4 spored; cheilocystidia 21–36 × 8–14 μm, clavate to subclavate, crowded; pleurocystidia, pileocystidia and caulocystidia absent.

Holotype:— INDIA. West Bengal: Kolkata, Salt Lake, Central park, 22°35’18.3”N, 88°25’02.8”E, 6 m elev., 09 July 2015, K. Acharya & A. K. Dutta, CUH AM031 .

Description:— Pileus 8–23 mm diam., infundibuliform, yellowish white (2A2) to greyish yellow (1-2B3, 3-4B4) or dull yellow (3B3) to light orange (5A4), unchanging on bruising, becoming translucent with KOH, glabrous, margin striate to sometimes eroded, often so deeply rimos that the entire pileus divides into two to three halves; context thin (<1 mm), yellowish white (4A2), becoming translucent with KOH. Lamellae up to 1–2 mm broad, decurrent, at first white, becoming concolorous to the pileus in age, subdistant to moderately close (L = 22–28, l = 1–2), even to slightly wavy or eroded, concolorous. Stipe 12–22 × 1–3 mm, central to slightly eccentric, cylindrical, curved, gradually tapered towards base, slightly bulbous at the point of attachment to the substrate, fibrous, hollow, surface greyish yellow (1-2B3, 3-4B4) to dull yellow (3B3), glabrous. Odour and taste indistinct. Spore-print white.

Basidiospores (5–)6.5–7.5(–8) × 5–6(–7.5) μm [X mr = 6.8–7.2 × 6.5–6.9 μm, X mm = 6.9 ± 0.8 × 6.7 ± 0.7 μm, Q mm = 1.1 ± 0.04, Q mr = 1–1.2, n = 20 spores, s = 2 specimens], globose to subglobose or broadly ellipsoid, smooth, hyaline, inamyloid, non-metachromatic in cresyl blue, truncate with prominent hilar appendage (1–1.5 μm long), I-guttate when viewed with KOH, thin-walled. Basidia 25–36 × 7–9.5 μm, clavate to broadly clavate, hyaline, thin-walled,

2–4 spored; sterigmata 2.5–4(–7) μm long, cylindrical. Basidioles 30–34 × 7–9 μm, cylindrical to clavate, hyaline,

oil granules present when viewed with KOH, thin-walled. Pleurocystidia absent. Lamellae edge sterile, crowded with cystidia. Cheilocystidia (21–)25–29(–36) × (7–)10–12(–14) μm, clavate to subclavate, hyaline, moderately thick-walled. Lamellar trama hyphae interwoven, slender, 3–10 μm broad, filamentous, hyaline, inamyloid, thin- to slightly thick-walled. Pileipellis an epicutis, hyphae 3–10 μm broad, cylindrical, hyaline to pale yellow when viewed with KOH, inamyloid, non-gelatinous, thin-walled. Pileocystidia absent. Pileus trama hyphae interwoven, 3–15 μm broad, non-gelatinous, hyaline, inamyloid, thin-walled. Stipe trama hyphae interwoven, 3.5–4.5(–6) μm broad, cylindrical, non-gelatinous, hyaline, inamyloid, thin-walled. Stipitipellis hyphae 3–4(–5) μm broad, cylindrical, often branched, non-gelatinous, hyaline to pale yellow, inamyloid, thin-walled. Caulocystidia absent. Clamp connections present in all the tissues.

Habit and habitat:—Solitary to gregarious, on dead and decayed wood of Mangifera indica L.

Additional specimen examined:— INDIA. West Bengal: Kolkata, Salt Lake, Central park, 22°35’20.0” N, 88°24’59.4” E, 5 m elev., 09 July 2016, A. K. Dutta & K. Acharya, CUH AM122.

Molecular phylogeny:—An alignment of 712 nucleotides in the final dataset was produced and analyzed. Each of the ML analysis iterations recovered a single tree of which the likelihood values did not differ significantly. Bayesian analyses reached a standard deviation of split frequencies of 0.004 after one million generations. The trees generated using the ML and Bayesian analyses (BA) were identical in topology. Therefore, only the phylogenetic tree generated using ML analysis has been presented here ( Figure 3 ; -lnL = 9257.028122). Figure 3 highlights branch support values recovered by ML and posterior probabilities (PP) derived from the Bayesian majority-rule consensus tree (MLBS: ≥ 50%, PP: ≥ 0.50).

Figures

FIGURE 1. Trogia benghalensis (CUH AM031). Field photograph of the basidiomata. Scale Bar: 10 mm.

FIGURE 2. Microscopic features of Trogia benghalensis (CUH AM031, holotype). a. Basidiospores; b. Basidia and basidioles; c. Cheilocystidia; d. Hyphal arrangement in the pileipellis. Scale Bars: a–c = 5 μm; d = 10 μm.

FIGURE 3. Phylogram generated from maximum likelihood (RAxML) analysis using a GTR+I+G model of nucleotide substitution (-lnL = 9257.028122) based on nrITS sequence data. Numbers to the left of / are Maximum likelihood bootstrap (MLBS) support, and those to the right indicate the Bayesian posterior probabilities (PP, in bold). MLBS values ≥ 50% and PP> 0.50 are shown. The scale bar represents the expected changes per site. The newly generated sequences are indicated by an asterisk (*), and the newly described taxon is placed in bold font to highlight its phylogenetic position in the tree. GenBank accession numbers for all of the sequences are provided in the tree with their country of origin.