Calonarius caesiofulvus Niskanen, Liimat. & M. E. Sm., sp. nov.
Index Fungorum number: IF 900300; Mycobank number: MB 900300; Facesoffungi number: FoF 14857; Figs. 1a, 2a, 3
Etymology – The name refers to the colours of the basidiomes.
Holotype – K-M 001434088.
Pileus 4–10 cm in diam., at first hemispherical, then low convex to almost plane with a long-incurved margin, innately fibrillose, at first pale greyish purple, becoming yellow on the margin and brown in centre, viscid. Lamellae crowded, yellow. Stipe 4–7 cm long, 1–2 cm thick at the apex, marginate bulbous, pale yellow, covered up to halfway by a bluish purple universal veil. Context in pileus white to very pale yellow, in stipe, and especially at the base of the stipe, yellow. Universal veil bluish purple. Mycelium white to yellow. Odour not recorded. Basidiospores 9.5–11×5–5.5 µm, narrowly amygdaloid-citriform, moderately to strongly coarsely verrucose. Some basidia with brownish purplish-red granulose contents in 5% KOH. ITS sequence (GenBank ON843392, ex holotype) distinct from other members of Calonarius and with 97% similarity to the closest known species C. alcalinophilus.
Habitat and distribution – In deciduous forests with Fagaceae and so far known from Florida, USA.
Material examined – USA. Florida, Gainesville, University of Florida campus, under oak, 12 January 2015, coll. Richard Kneal, T. Niskanen 14–167, K-M 001434088 (holotype in K-M; isotype in H); Gainesville, Rock Creek Neighborhood, under oaks and pines, 10 January 2017, coll. Matthew E. Smith, MES-2020, FLAS-F-60313 (FLAS).
GenBank numbers – TN14-167: ITS=ON843392; FLASF-60313: ITS=MF074799.
Notes – The species can be recognized by the combination of yellow lamellae, pale yellow stipe, initially greyish purple pileus and narrowly amygdaloid-citriform, 9.5–11×5–5.5 µm basidiospores. It belongs to Calonarius subgenusFulvi section Fulvi.
Figure 1 – Basidiomes of the species of the genus Calonarius. a Calonarius caesiofulvus (K-M 001434088, holotype). b Calonarius nobilis (K-M 001434089, holotype). c Calonarius pacificus (K-M 001434090, holotype). d Calonarius pulcher (K-M 001434092, holotype). e Calonarius subcorrosus (K-M 001434093, holotype). Photographs: a Matthew E. Smith, b–e Kare Liimatainen
Figure 2 – Basidiomes of the species of the genus Calonarius. a Calonarius caesiofulvus (K-M 001434088, holotype). b Calonarius nobilis (K-M 001434089, holotype). c Calonarius pacificus (K-M 001434090, holotype). d Calonarius pulcher (K-M 001434092, holotype). e Calonarius subcorrosus (K-M 001434093, holotype). Drawings: Tuula Niskanen. Scale bars: 10 µm
Figure 3 – The best scoring RAxML tree of the genera Calonarius and Mystinarius based on the ITS region. Related sequences were retrieved from GenBank. Twenty-five specimens were included in the analysis of the ITS region which comprises 663 characters after alignment. The tree is rooted with Mystinarius. Estimated base frequencies were: A=0.246760, C=0.199165, G=0.201141, T=0.352933; substitution rates AC=0.954938, AG=3.189949, AT=1.426518, CG=0.990207, CT=5.977045, GT=1.000000, gamma distribution shape parameter α=0.312392. 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 subgenus of the species is indicated after the collection/GenBank no. of each specimen