I had heard that people in Northern Europe used pings in curdling
milk (I believe) and also for medicinal purposes. Frequently, whole
leaves were applied to wounds, and I understand scientists have found
a serious basis for this application.
This discussion of pings does remind me of something that's been
nagging me, though. I'm growing a Pinguicula moranensis (variety "G"
from California Carnivores) and it's putting out one new leaf after
another. As soon as the new leaf opens fully, though, one of the
older ones dies so there is a rosette with no more than five
reclining leaves at any one time. My plant has also not flowered, and
I'm not sure how dry I should allow it to get once it forms its
winter rosette.