Do you know what it is? Species or hybrid? Where did you get it? Was it grown from seed? Sometimes seedlings from certain crosses will do this and never bloom. It could also be due to maturity, heat, or fertilizer issues. Do you fertilize it? Too much nitrogen could also be an issue.

Hi. I don't know what species it is, but it seems to be a common passionflower. I bought it at a nursery, & it was already a decent size. As for fertilizer, I really haven't fertilized it. Do you think I should? Thanks so much for your help!

Your plant is probably stressed. You may want to try feeding it some compost or other low-nitrogen fertilizer and make sure it gets plenty of water.

THANKS!