These hazelnuts are grown from seeds from Slate European Hazelnut (Corylus avellana), sourced from Grimo nursery. Don't know much about them, but they were the only variety aside from Yamhill that produced a crop through the infamous 2021 pacific northwest heat dome.
Sale to OR, WA prohibited: https://www.nationalplantboard.org/state-law--regulation-summaries.html
Photo credit: I, Colae, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons