My plants came from Potterton and Martin in 1981, and were listed as caerulea / lutea mixed, as the two species are almost indistinguishable in leaf. I had three plants, and they all turned out to be Pinguicula caerulea. I grew it for a number of years and distributed a great many. I also had seed stored in the freezer for many years, but it was thrown out a decade ago, along with some long overlooked beefburgers and some packets that may have had seed in, but which no-one had the courage to open!