Calonarius pacificus Niskanen, Liimat. & Bojantchev, sp. nov.
Index Fungorum number: IF 900302; Mycobank number: MB 900302; Facesoffungi number: FoF 14859; Figs. 1c, 2c, 3
Etymology – The species was first found in California, a state in the Western United States by the Pacific Ocean.
Holotype – K-M 001434090.
Pileus 5–9 cm in diam, at first hemispherical, then low convex to almost plane, can be quite purplish when young
but becoming more and more ochre brown with age, with small, dark yellowish brown patches in the centre, glutinous. Lamellae crowded, pale brownish purple when young, becoming somewhat darker brown and losing the purple tint when old. Stipe 6–10 cm long, 1–2 cm thick at the apex, up to 4.5 cm at the base, with a marginate bulb, completely purple or upper part of the stipe purple when young, later very pale ochre brown. Context in pileus at first purple/white marbled hygrophanous, becoming pale yellow with age and on exposure, in the stipe or apex of the stipe purple/white, at the base of the stipe brownish ochre/white marbled hygrophanous. Mycelium white with yellowish brown patches. Universal veil not recorded. Odour indistinct. Basidiospores 12.5–14.5×6.5–7.5 µm, amygdaloid-citriform to citriform, moderately, coarsely verrucose. Part of the basidia with pale yellowish contents. ITS sequence (GenBank ON843394, ex holotype) distinct from other members of Calonarius and with 97% similarity to the closest known species C. suaveolens.
Habitat and distribution – In oak forests and so far known from California, USA.
Material examined – USA, California, Humboldt Co., Willow Creek, camping site, live oak forest, 30 November 2012, K. Liimatainen, J. Olsson, T. Niskanen 12–172, 001434090 (holotype in K-M; isotype in H); Santa Cruz Co., Scotts Valley, NAMA Foray site 12, 15 December 2012, K. Liimatainen, T. Niskanen 12–332, 001434091 (K-M).
GenBank number – ITS=ON843394.
Notes – Characteristic for Calonarius pacificus are the purple colours in all parts of basidiomes, at least when young, large basidiospores and habitat with oaks in Western North America. The morphology supports its placement in the C. subgenus Calochroi as a sister species to European C. suaveolens, although the placement of C. suaveolens in the C. subgenus Calochroi was not always been well supported by the previous phylogenetic studies (Frøslev et al. 2007; Liimatainen et al. 2022).
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