My Vanderplank book says, "It (p. mixta) is found wild in the mountains of Venezuela, Colombia, Ecuador, southern Peru and Bolivia at altitudes between 2500 and 3600 metres."
And my Ulmer and MacDougal book says, "Where the natural range of passiflora mixta overlaps with that of another tacsonia, it is generally p. mixta that is found in the lower regions, from 1700m upward, while other species, often p. cumbalensis, prefer the cooler mountaintops. At times, hybrid forms occur in the transition zones. Very often, p. mixta proceeds to altitudes of up to 3300m but rarely beyond that."
I don't see how it could possibly be overly aggressive where you are - if it were me, I'd plant it, and if it did indeed invade unwanted spaces, I'd just pull it up.
Do you see sword-billed hummingbirds where you are?
Sherry

Thank you Sherry, yes I had one visiting my feeder for a couple of days and I want them to come back. I have lots of Datura which is supposed to be one of their necter sources but I haven´t seen them at it.

There's a picture of a sword-billed hummer in one of my books feeding on a beautiful p. mixta flower - what an astounding bill!
But then South and Central America get so many beautiful and interesting hummingbirds - up here in the east, we only get the little ruby throats.
I'd love to see pictures of your hummingbirds and plants! Like I said, if it were me, I'd plant p. mixta, but I'd also plant any and all of the tacsonia passis that I could!
Sherry

Misssherry I have lots of photos over on the hummingbird forum posted under Pitter2 including the Sword-billed. Thank you for the reccomendations.

http://www.network54.com/Forum/439743/

Plant it. As Sherry said- if it goes crazy, kill it. Or even better.. Cut it back & send the rest of us the cuttings.
:)