Calocybella dicholamellata K.P.D.Latha, K.N.A.Raj & Manim., 2020

D, K. P., Latha, eepna, A, K. N., Raj, nil & Manimohan, Patinjareveettil, 2020, Diversity of the genus Calocybella Vizzini, Consiglio & Setti in Kerala State, India, Cryptogamie, Mycologie 20 (8), pp. 147-156 : 150-153

Calocybella dicholamellata K.P.D.Latha, K.N.A.Raj & Manim. , sp. nov.

( Fig. 1 )

MYCOBANK NUMBER. — MB 833492.

SYSTEMATIC POSITION. — Basidiomycota, Agaricomycetes, Agaricales , Lyophyllaceae , Calocybella .

HOLOTYPE. — India. Kerala State, Kollam District, Thenmala, Kattilapara , on humus-rich soil, among decaying litter, 17.VIII.2013, K. P. Deepna Latha DKP134 (holo-, CAL [ CAL 1242 ]). GenBank no. ITS: ( CAL 1242 : MN708209 ; DKP552: MN708210 ).

ETYMOLOGY. — The epithet refers to the furcate lamellae of this species.

DIAGNOSIS. — Differing from Calocybella lohitha K.P.D.Latha & Manim. in having a brownish yellow pileus with a somewhat pruinose surface, furcate and emarginate lamellae with a decurrent tooth, a brownish orange stipe which is slightly recurved-squamulose towards the apex, slightly broader basidiospores, 4-, 2- and 1-spored basidia, slightly gelatinised hyphae of both the lamellae and pileus trama, non-gelatinised hyphae of the pileipellis that turn reddish brown in KOH, a cutis-type stipitipellis disrupted by solitary or small clusters of flaring-out hyphae towards the apex, and a distinctive nrITS sequence (MN708209).

HABITAT AND DISTRIBUTION. — In small groups, on humus-rich soil, among decaying litter. Known only from Kerala State, India.

ADDITIONAL SPECIMENS EXAMINED. — India. Kerala State, Kollam District, Thenmala, Kattilapara, 20.VII.2011, K. N. Anil Raj AR775 (AMH 10035); 03.XI.2015, K. P. Deepna Latha DKP411 (AMH 10036); Kozhikode District, Janakikad Forest, Maruthonkara, 13.VII.2019, K. P. Deepna Latha & K. N. Anil Raj DKP552.

DESCRIPTION

Basidiocarps

Small, collybioid.

Pileus

6-21 mm diam, convex or somewhat conico-convex with a small umbo; surface brownish yellow (5C7/OAC790), hygrophanous and becoming slightly paler, not striate, somewhat pruinose all over; margin slightly incurved when young, becoming decurved with age, entire or somewhat wavy.

Lamellae

Emarginate with a small decurrent tooth, furcate, slightly transvenose, moderately crowded, greyish orange (5B5/ OAC792), up to 3 mm wide, with lamellulae of 3-7 lengths; edge entire, concolourous with the sides.

Stipe

16-43 × 2-3.5 mm, central, terete, equal or slightly tapering towards the apex, fistulose; surface greyish orange (5B4/ OAC793) at the apex, brownish orange (5C6/OAC776) towards the base, appressed-fibrillose all over, slightly recurvedsquamulose towards the apex; base slightly enlarged, with profuse, white basal mycelium and yellowish mycelial cords.

Context

Up to 3 mm wide, yellowish brown (5D8), soft, no colour reaction when treated with 5% KOH or 10% ammonia.

Odour

Indistinctive.

Taste

Indistinctive.

Spore print

Not obtained.

99/1.0 Calocybella dicholamellata , sp. nov., MN708210 -/0.65 Calocybella dicholamellata , sp. nov., MN708209 Calocybella lohitha KU 366465 Calocybella pudica KP 858000 (= Calocybella juncicola ) 73/0.99 100/1.0 Calocybella pudica KP 858002 (= Calocybella juncicola ) Calocybella pudica KP 858003 (= Calocybella juncicola ) Calocybella pudica KP 858001 (= Calocybella juncicola ) 66/0.96 Calocybella swetha KU 366467 86/0.99 Calocybella dominicana KY 363575 Calocybella babruka KU 366466 Gerhardtia citrinolobata KY 363576

100/1.0 Gerhardtia highlandensis GU 734744 -/0.52 Gerhardtia highlandensis FJ 601808 -/0.70 97/0.83 Gerhardtia borealis KP 858004 Gerhardtia borealis UDB 011377 100/1.0 Gerhardtia sp. EF421103

Myochromella boudieri AF 357047 99/1.0 Myochromella boudieri DQ 825427 Myochromella boudieri AF 357046 98/1.0 98/1.0 Myochromella inolens AF 357045 Sagaranella gibberosa AF 357041 100/1.0 Lyophyllum favrei AF 357034 Lyophyllum ochraceum AF 357033 67/0.99 93/1.0 73/0.93 Calocybe fallax JF 907774 Rugosomyces chrysenteron UDB 015551 100/1.0 Rugosomyces ionides UDB 015551 99/1.0 Calocybe ionides AF 357029 95/1.0 Calocybe obscurissima AF 357031

100/1.0 60/0.83 Calocybe gambosa UDB 011371 77/0.90 100/1.0 Calocybe gambosa AF 357027 Calocybe carnea AF 357028 Calocybe gangraenosa AF 357032 77/0.90 Asterophora parasitica AF 357038 Tephrocybe palustris AF 357044 100/1.0 Asterophora lycoperdoides AF 357037 72/0.99 Blastosporella zonata EU 708340 100/1.0 Arthromyces matolae NR _119702 96/1.0 Arthromyces matolae EU 708339 Tricholomella leucocephala JN 790692 100/1.0 Tricholomella constricta AF 357036 Ossicaulis lachnopus HE 649955 100/- Ossicaulis lignatilis HE 649951 0.08 substitution per site

Basidiospores

4-6 (7) ×3-3.5 (4) (5.15± 0.67 ×3.23 ±0.33) µm, Q =1.14-2.16, Qm = 1.60, pip-shaped, hyaline, thin- to slightly thick-walled, acyanophilous, inamyloid, surface looking smooth under the light microscope, but with irregular verrucae under the SEM.

Basidia

20-25 × 5-7 µm, clavate, with a pale yellow wall pigment,reddish brown in KOH, thin-walled, siderophilous, mostly 4-spored, at times 2-spored or single-spored; sterigmata up to 6 µm long.

Lamella-edge

Fertile.

Pleurocystidia

Absent.

Cheilocystidia

Absent.

Lamellar trama

Subregular; hyphae 3-11 µm wide, sometimes slightly gelatinised, thin- to slightly thick-walled (up to 1.5 µm thick), with a smooth wall with a pale yellow wall pigment, hyaline in KOH, inamyloid.

Subhymenium

Poorly developed.

Pileus trama

Interwoven composed of slightly gelatinised hyphae; hyphae 3-10 µm wide, thick-walled (up to 2 µm thick), with a smooth wall with a pale yellow wall pigment, pale reddish brown in KOH, inamyloid.

Pileipellis

A cutis; hyphae 2-13 µm wide, with a thin to thick (up to 1 µm thick), smooth wall with a pale yellowish brown wall pigment, reddish brown in KOH.

Stipitipellis

A cutis often disrupted by solitary or short patches of flaring out hyphae towards the apex; hyphae 2-6 µm wide, with a thin to slightly thick (≤0.5 µm thick), smooth wall with a pale yellowish brown wall pigment, reddish brown in KOH, inamyloid.

Caulocystidia

Absent.

Clamp connections

Observed on all hyphae.

NOTES

This new species is different from all the three Calocybella species previously described from Kerala by Latha et al. (2016). Calocybella lohitha , differs in having greyish red basidiocarps with a finely granulose pileus which is tacky when wet, sinuate and non-furcate lamellae, a longer stipe (30-50 mm) lacking squamules at the apex, slightly narrower (2-3 µm) basidiospores, consistently 4-spored basidia, hyphae of lamellar trama turning greyish violet in KOH, a duplex-type pileus trama lacking gelatinisation, slightly gelatinised hyphae of the pileipellis, and a cutis-type stipitipellis. Calocybella babruka K.P.D.Latha & Manim. , is distinguished from C. dicholamellata , sp. nov., in having slenderly tricholomatoid, brownish basidiocarps, a planoconvex pileus with a granulose surface and a lobate margin, non-furcate lamellae, a shorter (up to 30 mm) and slightly compressed, stuffed stipe devoid of any squamules at the apex,ellipsoid to oblong-ellipsoid basidiospores, consistently 4-spored basidia, the occasional presence of crassobasidia, slightly gelatinised hyphae of the pileipellis lacking any discolouration in KOH, and a cutis-type stipitipellis embedded in a resinous material. Calocybella swetha K.N.A.Raj & Manim. , has slenderly tricholomatoid, whitish basidiocarps, a non-hygrophanous pileus with a velutinous surface and a fluted or rarely lobate margin, a shorter stipe (up to 30 mm) which is slightly compressed and tapered towards the base, and a scarcely pruinose surface, ellipsoid to broadly ellipsoid, smooth basidiospores, consistently 4-spored basidia, the occasional presence of crassobasidia, a pileus trama not turning colour in KOH, and a trichoderm-type pileipellis with slightly gelatinised hyphae.

Calocybella juncicola , the only known European species, is distinguished from C. dicholamellata , sp. nov., by an orange to brownish orange, non-hygrophanous pileus, adnate-emarginate, orange yellow lamellae with paler edges, a pale yellow stipe which is finely pruinose and tapered towards the base, a reddening context, a mealy odour and taste, cyanophilous basidiospores and consistently 4-spored-basidia ( Corriol et al. 2017).

Calocybella dominicana , a species from the Dominican Republic, differs from C. dicholamellata , sp. nov., in having an ochraceous orange, somewhat silky pileus with a darker centre, white, close lamellae, a white-pruinose stipe with a surface reddening on handling, a mealy odour and taste, strongly warty basidiospores, consistently 4-spored basidia, regular to slightly divergent lamellar trama, pileipellis hyphae with some repent clavate terminal elements, and a gregarious habit ( Vizzini et al. 2017). The key characters of all the known Calocybella species are listed in Table 1.

A comparison of the newly generated nrITS sequence of C. dicholamellata , sp. nov., (644 bp) with those sequences available in the GenBank suggests that the former has a distinct nrITS sequence. Calocybella babruka (KU366466) resulted as the closest hit with 86.99% identity in BLASTn search. The phylograms inferred from both the ML and BI analyses were identical in topology. Hence only the ML tree is shown in Fig. 2. The phylogram confirmed the placement of C. dicholamellata , sp. nov., within the genus Calocybella . All Calocybella species together recovered as a monophyletic group with significant bootstrap (73% MLB) support and high BI posterior probability (0.99 BPP) value. Within this clade, the two sequences of C. dicholamellata , sp. nov., were found to be conspecific and is sister to a species from tropical India, C. lohitha .

Figures

FIG. 1. — Calocybella dicholamellata K.P.D.Latha, K.N.A.Raj & Manim.,sp.nov.,DKP134 (CAL 1242,holotype):A, basidiocarps in natural habitat;B, basidiospores; C, basidiospore under SEM; D, siderophilous basidium; E, basidia;F, pileipellis;G, stipitipellis;H, hypha of pileus trama. Scale bars: A, 10 mm; B, D, E, H, 10 μm; C, 1 μm; F, G, 20 μm.