I have been growing some gentians in pots for a few years and they have now come into bloom, lovely gentian blue bloom, but they are not what I thought they were. I got the seed from a member seed-exchange and mix-ups happen. In fact, mislabelled seed occasionally happens even when purchasing seeds from reputable seed vendors.
So, my summer-flowering gentians are probably the European species Gentiana dahurica or Dahurian gentian, a species with a reputation of being relatively easy in gardens. They sure look like the pictures on the internet. I do not usually sell non-native species but these are much too nice to compost. I already have an European species, Willow Gentian, in my woodland garden and I like it a lot, but I don’t really have any place for Dahurian Gentians. So I am offering them for sale, at a somewhat reduced price. If you would like some blooming-sized Dahurian (maybe, probably) Gentians, Beaux Arbres Native Plants has them.