In the US these are usually considered wild blueberries, and the best ones of course come from Maine. The wild Maine blueberries[0] are a Vaccinium that grow on scrubby bushes low to the ground that can be hand-picked or harvested from blueberry barrens[1] with special rakes. Much better than the big supermarket blueberries in terms of flavor and pie-making ability. I'm curious to try some of the Swedish variety to see how they compare!

[0] - https://extension.umaine.edu/blueberries/home/public-2/

[1] - example blueberry barren: https://downeast.com/images/blueberry-barrens-5/