Re-evaluating some common and rare Cortinarius species

Speaker: Andy Nilsen. Work by Andy Nilsen and David Orlovich.

Herbaria hold invaluable biodiversity data, but many collections, particularly historical ones, lack DNA barcodes necessary for accurate identification. This is especially problematic for type collections, which serve as a taxonomic reference for a species. Older specimens are often degraded, making successful DNA barcoding challenging with traditional methods. We applied both traditional and modern sequencing techniques to type and non-type collections from the New Zealand Fungarium (PDD) and the State Herbarium of South Australia (AD), successfully retrieving DNA from specimens over 100 years old.

One key application of this work has been revisiting New Zealand sequestrate Cortinarius species and the elegant blue webcap, Cortinarius rotundisporus. The true identity of these species has long been difficult to establish due to morphological similarities and a lack of molecular data from type collections. Here we discuss current progress in establishing these species phylogenetic placements and some of the difficulties arising from this research