I have found this one of the most difficult of the chysanthus/biflorus hybrids to maintain in Newfoundland, but this stock, which came from Potterton & Martin in 1979 has just survived. I think it is the genuine "Lady Killer" with very clear cut white bordered deep purple outer tepals. (I have also been supplied with forms like Todd's under this name, but I think they are different hybrids.)
This clump of 'Lady Killer' crocus show the lovely two-tone effect of their flowers.
A view from above
Small clump of Lady Killers basking in the sun
Folded for the night, you can see the purple outer stripe. Planted Fall 2010; Photo from 21 Mar 2011