Amanita variicolor Y. Lamoureux

Lambert, Herman, Fortin, Guy, Labbe, Roland, Labrecque, Jacqueline, Berube, Jean A., Landry, Jacques, Ilyukhin, Evgeny, Margaritescu, Simona, Moncalvo, Jean-Marc & Lamoureux, Yves, 2018, Validation of two Amanita species from eastern North America: A. rhacopus sp. nov. and A. variicolor sp. nov., MycoKeys 38, pp. 47-57 : 47

Amanita variicolor Y. Lamoureux sp. nov. Fig. 2

A. inaurata ss. Pomerl. p. p.; A. ceciliae ss. auct. amer. p. p.

non Amanita inaurata Secr. ex Gillet, Hyménomycètes ( Alençon): 41 (1874) [1878]

non Agaricus ceciliae Berk. & Broome, Ann. Mag. nat. Hist., Ser. 2 13: 396 (1854)

Diagnosis.

Amanita variicolor differs from other species of Amanita sec. Vaginatae by its versicolour (straw-yellow, orange-brown to blackish brown) pileus, stipe white then covered with brown olive to orange chevron-forming fibrils, stipe base dark orange to rusty, universal veil grey to orange-grey leaving small to large flakes on the pileus and one or two strips at the stipe base, found mainly with Abies and Betula .

Holotype.

CANADA, Québec: Rawdon, in a mixed forest of Abies balsamea and Betula papyrifera , on moist soil close to a bog, 19 August 2003, CMMF003787, ITS Genbank accession number MG734656.

Etymology.

The epithet variicolor refers to the very variable colour of the pileus.

Description.

Pileus 40-100 mm wide, ovoid to rounded conic at first, then plane with an umbo, smooth, olive yellow, straw yellow, bronze, olive brownish to brown-black and then tinged with olive or orange yellow towards the margin, at times darker in the centre and over inner ends of marginal striations, often with small to large grey or orange grey velar flakes, margin striated. Lamellae free, subcrowded, whitish, greyish to salmon tints. Stipe100-200 × 8-17 mm, cylindrical (not bulbous or barely), flocculose and white at first, typically covered all over by chevron-forming rusty-orange fibrils on a whitish background when mature, without annulus, base always rusty orange with one or two greyish-orange velar strips. Universal veil friable, grey to orange grey, often leaving small to large flakes on the pileus and one or two strips at the stipe base. Partial veil absent. Context white, unchanging when cut or bruised, odour not distinctive, taste not recorded.

Basidiospores: [180/3/3] (8.2) 9.8-11.5 (13.3) × (7.1) 8.8-10.7 (12.2) µm, Q= 1.0-1.2 (1.3), Qm= 1.09, globose to subglobose, smooth, monoguttulate, hyaline, inamyloid and cyanophilous. Basidia 48-65 × 14-19 µm, clavate, 4-spored with sterigmata up to 8.5 μm long. Subhymenium composed of irregular globose to subglobose 11-20 (25) × (6) 10-15 µm cells. Lamellar trama bilateral consisting of cylindro-clavate, clavate, fusiform to subfusiform, abundantly inflated 28-40 (55) × 13-20 µm cells mixed with thin-walled, hyaline, 2-6 μm wide filamentous hyphae and rare vascular hyphae. Volva remnants composed of 4.5-7.5 µm wide filamentous hyphae terminated by 25-60 µm wide subglobose to globose and inflated cells often in chains and rare to absent vascular hyphae. Pileipellis composed of an upper layer of 2.5-6 µm wide radially orientated gelatinised hyphae and a subpellis of mainly filamentous 4-12 µm wide hyphae mixed with cylindrical to fusiform inflated 50-100 × 13-24 µm cells often in chains and some 7-10 µm wide vascular hyphae. Pileus context composed of equal amounts of (4) 5-12 µm wide filamentous hyphae, sometimes inflated, more or less ramified and cylindrical, subfusiform to fusiform 40-110 × 10-33 µm inflated cells often in chains, with some 7-10 (12) µm wide vascular hyphae, sometimes inflated, rarely ramified. Stipitipellis composed of 3-5 (6) µm wide filamentous hyphae terminated by clavate 50-90 (120) × (12) 16-23 µm cells containing reddish-brown pigments. Stipe context composed mainly of cylindrical 150-350 × 20-35 µm cells in chains, 4-13 µm wide filamentous hyphae and some 7-10 µm wide vascular hyphae. Clamps absent.

Ecology and distribution.

Solitary, sometimes scattered to gregarious, in stands of conifers ( Abies , Picea , Pinus , Tsuga ) mixed with Betula , on sub-hydric to mesic soil, never seen in plantations, from July to September in Québec and Ontario. Possibly also present further south (see Discussion).

Specimens examined.

Canada, Québec: Québec, Base de plein air La Découverte, H. Lambert (HL0846), 15 August 2010. Lac-Beauport, Chemin de la Chapelle, H. Lambert (HL0852), 22 August 2010. Sacré-Sœur-sur-le Fjord, Rivière Sainte-Marguerite, fosses 3, 4, 5, H. Lambert (HL0257), 17 August 2008 (Genbank accession number MG734657). Sacré-Sœur-sur-le Fjord, Parc Saguenay, H. Lambert (HL051), 2015. Ontario: Algonquin Provincial Park, M. Didukh and B. Dentinger (TRTC156902), 1 October 2007 (Genbank accession number MG734655).