A garden full of fritillaries

As you can see, we have plenty of fritillaries in the garden at present. They love tihs particluar plant although,I am afraid to say, I have no idea what it is.
Good to get out of the kitchen for a break away from the various bits and species. On hindsight, starting with fitting a corner unit has proved to be an error.
 By the end of the process I will know the pitfalls and so avoid such schoolboy errors in the future - if one ever has to do this again.