I always thought Larkspur was just the common name for Delphiniums, but then I've never grown them so not very familiar with them. Looking through the database it looks like it might be 'Aurora Blue', but that doesn't match with what looks like might start with "Dark" for the common name... unless they're calling Dark Blue Larkspur? But then, I have run into a few wrong name plates there, just to add more confusion!