I think some variants of castexi are called tiger rays. I think there mau be another spieces called tigers as well...can't think of it off the top of my head. As far as I know castexi are about the same care level as motoro. I hate to speak out of school as I've never kept any castexi myself.
I haven't heard of a flower ray being called a tiger, though they do have a similar look and personalities. They tend to be more quiet, sensitive rays, especially when young. Not my pics, but these are flower rays-
This is a tiger ray-
The above are not tigers or flowers. They look like hybrids to me, however I'm far from a pro on IDs.
Castexi is a huge group of rays with several different looks, some do have a flower look to them. Castexi in general get enormous.
That is a big girl! John from ECZS, weird dude, he used to be a huge ray and fish supplier for the fish forums. He was banned a few years ago from what I recall. One of the few bringing in tigers I guess.