It's most likely Passiflora, but there are so many cultivars! You might post it in the Passiflora forum for a quicker, more authoritative ID.

Anna

It's some type of passiflora, looks like passiflora incarnata. We called them Maypops when I was growing up.

I planted some last year that didn't do much of anything. This year the plants are beautiful and blooming...finally. The Gulf Frits are really doing a number on mine. Next year I'm going to plant some in another garden just for them. I'm letting them chew away. After all, I planted it for them.

They have beautiful blooms!

B

Are you sure it's native? The only native passionvine we have in this area, and I think Texas, is P. incarnata/maypops, but the leaves don't look like maypops - too narrow and not shaped right. The leaves look a lot like P. 'Amethyst' also known as P. 'Lavender Lady' - I've got this one, and the gulf frits use it every year. It's a very common hybrid.
Do the flowers on your passionvine look like this?
{{gwi:465032}}
Sherry

I must agree with Sherry, those leaves aren't from P. incarnata, they're not the right shape...and I have TONS of it growing in my pasture, so it's a shape with which I'm familiar.

I wish something would come use my Passiflora in the garden!

Hmm, ok, I guess instead of "native" I should have said "native to my yard". Also, I have never seen its flower so that remains a mystery...