Cortinarius subiodes Niskanen, Liimat. & M. E. Sm., sp. nov.
Index Fungorum number: IF 900307; Mycobank number: MB 900307; Facesoffungi number: FoF 14864; Figs. 1c, 2c, 3
Holotype – K-M 001434108.
Etymology – The name refers to affinity with Cortinarius iodes.
Pileus 3–7.5 cm in diam, at first hemispherical, then low convex to almost plane, greyish blue to purple, and becoming pale yellow from the centre with age, innately fibrillose, somewhat slimy. Lamellae subcrowded to medium spaced, greyish blue when young, later greyish brown. Stipe 2–4.5 cm long, 0.7–1.5 cm thick at the apex, more or less marginate bulbous, white fibrillose. Context faint greyish or yellowish white with bluish tints. Universal veil glutinous, blue, forming a sock-like sheet or some belts at the bottom of stipe. Mycelium white. Odour in lamellae sweet. Basidiospores 9.5–10.5×6–6.5 µm, ellipsoid, moderately verrucose. Basidia hyaline. ITS sequence (GenBank ON843412, ex holotype) distinct from other members of Cortinarius and with 98% similarity to the closest known species C. iodes.
Habitat and distribution – In mixed forest (oaks and Pinus) and so far known from Florida, USA.
Material examined – USA, Florida, Franklin Co., by the bridge, when entering to Franklin Co., boat ramp place, young oak-dominated forest with some Pinus, 26 December 2014, K. Liimatainen, T. Niskanen 14-075, 001434110 (K-M). Wakulla Co., Crawfordville, 306 Wakulla Beach Road, under Pinus, mixed deciduous and Pinus forest with some Quercus virginiana, Magnolia grandiflora and sweetgum, sandy soil, on calcareous bedrock, 27 December 2014, K. Liimatainen, T. Niskanen 14-078, 001434111 (K-M). Otter Lake Road, young evergreen oak and Pinus forest, on sandy soil, 28 December 2014, K. Liimatainen, T. Niskanen 14-099, 001434112 (K-M). Tallahassee Co., Lake Talquin State Forest, by the road 267, Bear Creek Educational forest, mostly evergreen oaks, 29 December 2014, K. Liimatainen, T. Niskanen 14–106, 001434113 (K-M). Alachua Co., Gainesville, Sweetwater Preserve, Eastern trail, Xeric oak forest with some pines, 9 January 2015, K. Liimatainen, T. Niskanen 14–132, 001434109 (K-M). loc. cit. 15 January 2015, K. Liimatainen, T. Niskanen 14–286, 001434108 (holotype in K-M; isotype in H).
GenBank numbers – TN14-286: ITS=ON843412; TN14-132: ITS=ON843413; TN14-075: ITS=ON843414; TN14-078: ITS=ON843415; TN14-099: ITS=ON843416; TN14-106: ITS=ON843417.
Notes – Cortinarius subiodes is easy to spot in the field due to its bright greyish blue to purple colours. The pileus and universal veil are slimy and the basidiospores are ellipsoid. The species belongs to C. cf. subgenus Camphorati, section Delibuti. The sister species C. iodes can be distinguished by relatively longer, cylindrical to slightly clavate stipe.
Figure 1 – Basidiomes of the species of the genera Cortinarius, Hygronarius and Mystinarius. a Cortinarius flaureifolius (K-M 001434094, holotype). b Cortinarius floridaensis (K-M 001434095, holotype). c Cortinarius subiodes (K-M 001434108, holotype). d Hygronarius californicus (K-M 001434114, holotype). e Mystinarius ochrobrunneus (CR 4064459, holotype). Photographs: a Matthew E. Smith, b–d Kare Liimatainen, e Joseph F Ammirati
Figure 2 – Basidiomes of the species of the genera Cortinarius, Hygronarius and Mystinarius. a Cortinarius flaureifolius (K-M 001434094, holotype). b Cortinarius floridaensis (K-M 001434095, holotype). c Cortinarius subiodes (K-M 001434108, holotype). d Hygronarius californicus (K-M 001434114, holotype). e Mystinarius ochrobrunneus (CR 4064459, holotype). Drawings: Tuula Niskanen. Scale bars: 10 µm
Figure 3 – The best scoring RAxML tree of the genera Cortinarius and Hygronarius based on the ITS region. Related sequences were retrieved from GenBank. Forty-nine specimens were included in the analysis of the ITS region which comprises 732 characters after alignment. The tree is rooted with Hygronarius. Estimated base frequencies were: A=0.242037, C=0.200516, G=0.214242, T=0.343206; substitution rates AC=1.323688, AG=3.480113, AT=1.611311, CG=0.756641, CT=4.952595, GT=1.000000, gamma distribution shape parameter α=0.362036. Maximum likelihood bootstrap values higher than 50% are given at the nodes. The holotype specimens retrieved from the GenBank are in bold and black. The new species are in bold and blue. The section of the species is indicated after the collection/GenBank no. of each specimen