There are several red leaf cannas with red flowers. The flowers vary in sizes, shape, and shade of red, so without a pic of the bloom too, we can't tell which one you have. Just to name a few common ones I'm familiar with, there's:
Red Stripe (doesn't look like yours is striped enough to be red-stripe)
Red King Humbert
It's rather difficult to re-name a canna when the name has been lost unless it's very distinctive. Even then, it could be a seedling from a hybrid, so it wouldn't actually be that hybrid, but rather the offspring from it if it grew from seeds.
You might get close to an identification but browsing the cannas listed at:
Thank you...You sure do have lots of canna beauties! When I get caught up at home, I would like to talk to you again, about purchasing a couple of trading a couple (if you are interested). I'm so glad you responded. Talk soon.
Hello to FL :)
Merry, if you have this as Black Knight, you don't have Black Knight.
BK's blooms are a lot larger and a black red.
Also, BK does not set seed.
Hello to GA, too :)
Palamino, I will trade ONLY for non diseased cannas which have been TOUGH to find these days outside here.
But due to good grower friends .. this season we now have CLEAN Florence Vaugh, Cleopatra, Louis Cotton, Polly Gay, and Wyoming.
And maybe or maybe not Eileen Gallo. Not sure yet on that one.
But it's been GREAT to find these heirlooms still clean :)
It's very hot to near 100ºf here today with high humidity.
I have to keep reminding myself this is PA .. ha