Cruentomycena uttarakhandina U. Singh & R.P. Bhatt, sp. nov.
Index Fungorum number: IF 557839; MycoBank number: MB 557839; Facesoffungi number: FoF 07738; Fig. 1
Etymology – Named after Uttarakhand, from where this mushroom was collected.
Holotype – CAL 1800
Basidiomata small-sized, mycenoid, 16–42×2–10 mm. Pileus 2–10 mm in diam., convex, centrally depressed, surface viscid to glutinous when moist, maddor red (9A7) to vivid red or cinnabar red (9A8), smooth; margin entire, incurved to decurved, sulcate, concolorous; pileus context concolorous, fleshy. Lamellae distant, sub-decurrent, concolorous to pileus, with lamellulae in 4 series of different lengths; lamellar edges slightly lighter than lamellar face, entire. Stipe 14–40 ×0.5–1 mm, central, curved, equal to slightly tapered at base, slimy, concolorous to pileus, darker when handling, unchanged after bruising; stipe context concolorous, fibrous, hollow. Taste and odour indistinct. Spore print not obtained. Basidiospores 8–9.2–11×3–3.4–4 μm (Q=2.25–2.69–3.14 μm, n=30), elongated, tapering asymmetrically toward hilar appendage, smooth, hyaline in KOH, weakly amyloid. Basidia 20–30×5–7 μm, sub-clavate to clavate, thin-walled, 2- to 4- spored; sterigmata up to 5 μm long. Pleurocystidia 32–45×9–14 μm, clavate to ventricose with rounded to acute apex, emergent up to 22 μm, arising from the trama. Cheilocystidia 22–30×7–11 μm, clavate to broadly clavate. Lamellar trama sub-regular to irregular, of somewhat inflated cells (wide up to 48 μm). Pileipellis an ixocutis, composed of repent, cylindrical hyphae (wide up to 4 μm), rarely clamped; terminal hyphae 34–39×3–4 μm, cylindrical with rounded apex; Pileus trama composed of inflated hyphae up to 34 μm wide, thin-walled. Stipitipellis an ixocutis, with parallel hyphae, thin-walled, up to 6 μm wide. Caulocystidia 52–79 × 7–10 μm, thin-walled, subcylindrical with tapered base.
Material examined – INDIA, Uttarakhand, Pauri district, Chaurikhal, growing solitary to gregarious, on leaf litters under Quercus sp. in mixed forest, 1981 msl, N30°02.389′ E079°03.406′, 1 August 2017, U. Singh, US 1510 (CAL 1800, holotype); Phedkhal, 1913 msl, N30°09.697′ E078°51.195′, 24 August 2018, U. Singh, US 1667 (CAL 1801, paratype).
GenBank numbers – ITS = MT126031 (holotype), MT126034 (paratype).
Notes – Cruentomycena uttarakhandina can easily be characterized by its small size, red colour basidiomata with viscid to glutinous pileus, distant lamellae with lamellulae in 4 series of different lengths, thin stipe, elongated basidiospores, clavate to sub-clavate basidia, clavate to ventricose pleurocystidia, clavate to broadly clavate cheilocystidia, subregular to irregular lamellar trama, an ixocutis pileipellis without pilocystidia and an ixocutis stipitipellis with subcylindrical caulocystidia (Fig. 1). Cruentomycena kedrovayae, C. viscidocruenta and C. orientalis may appear similar to C. uttarakhandina in terms of their small-size and red colour basidiomata. However, these three species all show morphological differences from C. uttarakhandina. Cruentomycena kedrovayae differs from present species by plane to subinfundibuliform pileus, thick (almost fold-like) lamellae, smaller stipe (8–13× 0.5–0.8 mm), ellipsoid and smaller basidiospores (6–8(–9)×3.5–4 μm), and absence of pleurocystidia (Petersen et al. 2008). Cruentomycena viscidocruenta is distinguished from C. uttarakhandina by larger pileus (4–11(–14) mm broad), subdistant lamellae, smaller stipe (6–25 mm long, 0.4–1 mm broad), slightly smaller basidiospores [(6.5–)8–10 × (2.5–)3–4.5 μm] and absence of pleurocystidia (Petersen et al. 2008). Cruentomycena orientalis distinctively differs from C. uttarakhandina by its smaller pileus (4–8 mm diam.), sub-distant lamellae, smaller stipe (15–35×0.7–1 mm), smaller and ellipsoid to oblong-ellipsoid basidiospores [(7.1–)7.9–9(–10.5)×(3.5–)3.8–4.3(–5.1) μm] and absence of pleurocystidia (Terashima et al. 2016). The ITS dataset consisting of 20 sequences (including our isolates: US 1510, represented by GenBank acc. no. MT126031 and US 1667, represented by GenBank acc. no. MT126034) of Cruentomycena, Resinomycena, Panellus and Mycena were analysed. Our isolated sequences were recovered as a distinct taxon (marked with blue font) in a strongly supported (98% MLBS, 1.00 BYPP; Fig. 2) clade and clustered with other species of Cruentomycena. The combination of morphological features and phylogenetic analysis corroborates the proposed taxon Cruentomycena uttarakhandina as a new species being distinct from all the
known taxa of Cruentomycena.
Figure 1 – Cruentomycena uttarakhandina (US 1510, holotype). a Habitat. b Basidiomata. c Basidiospores d Transverse section through hymenium showing basidia, pleurocystidia and lamellar trama. e Cheilocystidia. f Pleurocystidia. g Caulocystidia. Scale bars: a=20 mm, b = 10 mm, c, e–g=10 µm, d=25 µm
Figure 2 – Phylogenetic analyses were based on data set of nrITS sequences. Reference sequences were selected from relevant literature (Petersen et al. 2008), BLAST searches (Altschul et al. 1997) and data retrieved from GenBank (Clark et al. 2016). Species of Mycena are selected as the outgroup taxa (Petersen et al. 2008). Multiple sequence alignment was performed using MAFFT v.7 (Katoh and Standley 2013). Alignments were manually edited in BioEdit v 7.2.5 (Hall 1999). To change the multiple alignment format, Alignment Transformation Environment (ALTER) was used (Glez-Peña et al. 2010). Maximum Likelihood analysis was performed with the programme RAxML GUI 1.5 (Silvestro and Michalak 2012). One thousand bootstrap replicates were analysed to obtain nodal support values. Bayesian inference was computed independently twice in MrBayes v.3.2.2 (Ronquist et al. 2012), under different models. The best-fit substitution model of nucleotide evolution was carried out in MrModeltest 3.7 (Posada and Crandall 1998). Bayesian posterior probabilities (BYPP) were calculated in two simultaneous runs with Markov chain Monte Carlo (MCMC) algorithm (Larget and Simon 1999). Markov chains were run for 10 million generations, saving a tree every 100th generation. Default settings in MrBayes were used for the incremental heating scheme for the chains (3 heated and 1 cold chain), unconstrained branch length [unconstrained: exponential (10.0)] and uniformative topology (uniform) priors. The first 25% of trees was discarded as burnin (Hall 2004). Ex-type strain is in bold and newly generated sequences are in blue