Resurrection of Cortinarius coalescens: taxonomy, chemistry, and ecology

Abstract

Cortinarius coalescens Kärcher & Seibt is a rare European species of the subgenus Phlegmacium, section Phlegmacioides, neglected in recent molecular studies. New primers (CortF and CortR) designed for species in the section Phlegmacioides allowed to obtain ITS rDNA sequence data from the holotype collection of C. coalescens; according to the results, this epithet has priority over C. crassorum Rob. Henry ex Rob. Henry, C. pardinus Reumaux, and C. parargutus Bidaud, Moënne-Locc. & Reumaux. Morphological and ecological observations on recent collections of C. coalescens from the Czech Republic in comparison with the co-occurring C. largus are discussed. Nomenclatural and taxonomic comments on C. tomentosus Rob. Henry, C. balteatotomentosus Rob. Henry, and C. subtomentosus Reumaux are also provided. So far, C. coalescens is known with certainty from Germany, France, and the Czech Republic, where it grows in deciduous forests on acid to neutral soils. Arsenic and its compounds were determined in C. coalescens and related species of the section Phlegmacioides: C. largus, C. pseudodaulnoyae, and C. variecolor. Total arsenic concentrations were in the range 3.6-30.2 mg kg^-1 (dry matter) and arsenobetaine was the major arsenic compound.

Keywords: Arsenic; Arsenobetaine; Bioaccumulation; Cortinariaceae; Phlegmacioides clade; Soil.

Fig. 1

Sequenced isotype of Cortinarius coalescens (FR 0247030) contaminated by conidial fungi

Fig. 2

a Cortinarius coalescens found at Český Šternberk (21 August 2005, not documented by herbarium specimen). b Cortinarius coalescens collected at Běleč (PRM 923847). c, d Cortinarius coalescens collected at Český Šternberk (PRM 923845, duplicate FR 0070025). All photos by Jan Borovička

Fig. 3

Basidiospores of Cortinarius coalescens and Cortinarius largus under a scanning electron microscope (scale bars = 5 μm). a Cortinarius coalescens (FR 0070020, holotype). b Cortinarius coalescens (PRM 923845). c Cortinarius largus (FR 0070030). d Cortinarius largus (PRM 923846)

Fig. 4

Maximum likelihood phylogeny of the Phlegmacioides clade inferred from ITS rDNA sequence data. Branch support is indicated only when the Bayesian posterior probability and maximum likelihood bootstrap values are >0.90 or >70%, respectively. Sequences of species not being in the focus of this study are shown as compressed clades. Newly generated sequences are highlighted in bold. The bar indicates 0.01 expected change per site per branch

Fig. 5

Arsenic species in extracts of investigated Cortinarius spp. (in % of all detected arsenic species). AB: arsenobetaine, TMAO: trimethylarsine oxide, TETRA: tetramethylarsonium ion, AC: arsenocholine, DMA: dimethylarsinic acid

Fig. 6

Whole chromatograms and details of one extract of Cortinarius pseudodaulnoyae (ASP-70). a Anion-exchange conditions. b Cation-exchange conditions

Fig. 7

Cortinarius largus from Český Šternberk (PRM 923846, B-503b), where it shares the habitat with C. coalescens. Photo by Jan Borovička