I'm fairly sure it's not a hybrid. It's a Dianthus caryophyllus. Beyond that, I don't know much. Hopefully, someone else will chime in. It's actually a perennial, not an annual.

I will say, that species of carnation tends to flop and crawl around my garden. Maybe they're just taking advantage of that type of habit to say it's "cascading" when you put it in a hanging container? D. chinensis is more upright for me. Sweet William is hit/miss with that characteristic. Anything that smells nice and looks pretty is good enough for me!

Thanks I have it germinating right now. I will know more this summer.