Gomphidius pseudoglutinosus K. Das, Hembrom, A. Parihar & Vizzini, 2020

Rossi, Walter, Das, Kanad, Hembrom, Manoj Emanuel, Santamaria, Sergi, Parihar, Arvind, Ghosh, Aniket, Henkel, Terry W., Hofstetter, Valerie & Randrianjohany, Émile, 2020, Fungal Biodiversity Profiles 91 - 100, Cryptogamie, Mycologie 20 (4), pp. 69-107 : 78-83

95. Gomphidius pseudoglutinosus K. Das, Hembrom, A. Parihar & Vizzini , sp. nov.

(Figs 7-9)

Differs from other Gomphidius by nrITS sequence data and, morphologically, by the combination of the following features: color and size of the basidiomata (pileus 23-80 mm; stipe 40-90 × 10-25 mm), the presence of a glutinous superior annular zone, the yellow surface and context of the stipe base, the size of basidiospores (14.5-16.8-20.0 × 5.35-6.6-7.65 µm) and, finally, also by its exclusive occurrence under Larix griffithii Hook. f. in subalpine Himalaya.

HOLOTYPE. — India. Sikkim, North district, Dombang valley , 27°43’35.2”N, 88°45’15.2”E, 2920 m a.s.l., on the soil among mosses under Larix griffithii Hook.f. , 24.VII.2013, Kanad Das, KD 13-019 (holo-, CAL [ CAL1762 ]!).

MYCOBANK. — MB 830221.

GENBANK. — MK602650 (nrITS, holotype), MK602358 (nrITS, paratype).

ETYMOLOGY. — Referring to the affinity with G. glutinosus .

ADDITIONAL EXAMINED MATERIAL. — India. Sikkim, North district, Dombang valley, 27°44’05.6”N, 88°45’56.4”E, 2897 m a.s.l., on the soil among mosses under Larix griffithii Hook.f. , 22.VII.2013, Kanad Das, KD 13-004 (para-, CAL[CAL 1761]).

DESCRIPTION

Pileus

23-80 mm, broadly conical to pyramidal when very young, becoming convex, then plano-concave to broadly infundibuliform with a depressed centre at maturity; surface wet, strongly viscid with thick gluten, more or less smooth, glabrous, reddish golden to brownish orange (6-7C3) when young, then gradually white to greyish red (10A-B6) when gluten layer is eroded, brownish grey (10E2) on bruising, turning olive brown (4E4-5) with FeSO4; margin remains attached to stipe and covered/buried under glutinous velar attachment, incurved at maturity, often marked with thin grey-black lines of spore deposition.

Lamellae

Decurrent, close (c. 1/mm at pileus margin), unequal with lamellulae in four series, also forked at different distances, semi-transparent to smoky; edge concolorous.

Stipe

40-90 × 10-25 mm, cylindrical, broader above, gradually tapering at base, white and dry above annulus, lower half more or less lemon yellow to vivid yellow (3A8), becoming brownish with maturity or on bruising.

Annulus

Subapical, a broad, glutinous collar, blackish with spore deposition. Context of the pileus white, then pale red (7A3) or pale brownish, unchanging with guaiacol but turning English red to reddish brown (8D-E2) with FeSO 4.

Odour

Indistinctive.

Spore print

Black.

Basidiospores

14.5-16.8-20.0 × 5.35-6.6-7.65 µm, Q = 2.0-2.55-3.2, boletoid, apiculate, smooth, dark olivaceous brown, weakly dextrinoid.

Basidia

60-82 × 8-18 µm, clavate-pedicellate, 4-sterigmate; sterigmata 5-10 µm long.

Basidioles

Clavate with narrow stalk.

Pleurocystidia

92-162 × 10-17 µm, cylindrical to subfusiform, thin-walled, encrusted with thick crystals, hyaline in 3% KOH, coffee brown in Melzer’s reagent, with dense cytoplasmic contents.

Cheilocystidia

Similar but smaller, 55-98 × 9-20 µm.

Hymenophoral trama

Inamyloid.

Pileipellis

An ixocutis composed of repent hyphae submerged in thick gluten (10-20 µm thick beyond hyphal elements), 2.5-9 µm wide, irregularly inflated, loosely interwoven, smooth (mostly) or encrusted in a somewhat zebroid pattern, hyaline.

Stipitipellis

Similar to pileipellis but more compact, with parallel hyphae, 3-8 µm wide, infrequently encrusted; thromboplerous hyphae present below hyphal layer, 3-8 µm wide, with dense homogeneous cytoplasmic contents, smooth, pale yellow in 3% KOH.

Hyphae of basal mycelium

3-8 µm wide, infrequently clamped, hyaline, few hyphae are olivaceous brown in 3% KOH, smooth to infrequently encrusted.

Clamp connections

Absent.

NOTES

Gomphidius pseudoglutinosus K. Das, Hembrom, A. Parihar & Vizzini , sp. nov., representing the first report of the genus Gomphidius from India, is characterized by brownish orange to greyish red pileus that turns olive brown with FeSO4, decurrent smoky lamellae, white upper half and yellow lower half of stipe, glutinous annular band on upper half of stipe, thin-walled encrusted hymenial cystidia and its exclusive occurrence under Larix in subalpine Himalaya.

The genus Gomphidius currently encompasses some 21 accepted names (fide N. Wilson, https://mushroomobserver.org/project/show_project/162), but not all of these have reliable sequence data. When comparing our nrITS sequences through “Pairwise sequence alignment” with those of other Gomphidius deposited in GenBank, all are <97% similar with those of our species, with one exception: a sequence from neighbouring Yunnan, China, identified as G. ‘ aff. glutinosus ’ (EU791578, see Li et al. 2009), which might represent and earlier collection of our new species (sequence similarity of 99.63% for 84% query coverage).

Our phylogenetic analysis (Fig. 7) suggests, although without support, that our new species is most closely related to

100 EU706328 Chroogomphus orientirutilus China

0.02

FIG. 7. — Maximum Likelihood (ML) phylogram inferred from raxmlGUI ( Silvestro & Michalak 2012) based on nrITS sequences of Gomphidius . One thousand bootstrap replicates were analyzed to obtain nodal support values. Bootstrap support values (>70%) obtained from ML analysis are shown above or below the branches at nodes. Both collections of the novel Indian species are shown in red and the holotype is in bold.

the North American G. subroseus Kauffman and G. smithii Singer , and these three species are then suggested to be most closely related to G. glutinosus (Schaeff.) Fr. , originally reported from Europe but later also found in North America ( Miller & Miller 2006, Desjardin et al. 2015).Together, these four species form a significantly supported clade (77% BS) with G. oregonensis Peck , originally described from the Pacific North West and present in all the Pacific coast states. None of these other Gomphidius , however, is associated with Larix . The only other Gomphidius associated with Larix are the European G. maculatus (Scop.) Fr. , the Russian G. borealis O.K. Mill., Aime & Peintner , and the recently described G. albipes Y. Li & L.L.Qi from northeastern China ( Qi et al. 2017).

Gomphidius pseudoglutinosus K. Das, Hembrom, A. Parihar & Vizzini , sp. nov., is associated with Larix griffithii or Sikkim Larch, a tree found in Nepal, Sikkim ( India), Bhutan and China, which figures on the IUCN red list of threatened plants.

Order HYMENOCHAETALES Oberw.