New species of Cortinarius sect. Austroamericani , sect. nov., from South American Nothofagaceae forests

SAN-FABIAN, BEATRIZ; NISKANEN, TUULA; LIIMATAINEN, KARE; KOOIJ, PEPIJN W.; MUJIC, ALIJA B.; TRUONG, CAMILLE; PEINTNER, URSULA; DRESCH, PHILIPP; NOUHRA, EDUARDO; MATHENY, P. BRANDON; SMITH, MATTHEW E.

MYCOLOGIA.

ALLEN PRESS INC

Año: 2018 vol. 110 p. 1127 - 1144

0027-5514

In this study, we document and describe the new Cortinarius section Austroamericani. Our resultsreveal high species diversity within this clade, with a total of 12 recognized species. Of these, onlyC. rufus was previously documented. Seven species are described as new based on basidiomatacollections. The four remaining species are only known from environmental sequences. Allexamined species form ectomycorrhizal associations with species of Nothofagaceae and arecurrently only known from Argentinean and Chilean Patagonia. The phylogenetic analysis basedon the nuc rDNA internal transcriber spacer (ITS1-5.8S-ITS2 = ITS) and partial 28S gene (28S)sequences shows that this section is related to other taxa from the Southern Hemisphere. Speciesin this group do not belong to subg. Telamonia, where C. rufus was initially placed. Cortinariusrufus and the newly described C. subrufus form a basal clade within sect. Austroamericani that hasa weakly supported relationship with the core clade. Because the two species are morphologicallysimilar to species from the core clade and share their distribution and Nothofagaceae associations,we include them here as part of sect. Austroamericani sensu lato (s.l.) until more material isavailable to refine the delimitation.