Do you know which species of passiflora you have? What state do you live in?

I usually propagate my passifloras through cuttings, but some root much easier than others. If you can post a picture, or go to Google and look at some pics and get a species name, I'll try to help you.

I don't know what species it is, and neither does my friend. I just know that it is purple. I know my friends neighbor has tried many times to propogate this vine, with no success. It comes up absolutely everywhere so it seems like it woule eagerly grow! The plant I have is still very happy in the glass of water I have it in. It's been 12 days now since I pulled it out of the ground. I'll see if I can find a picture online that looks like the one my friend has.

I live in the Dallas, Tx area.

Look up Passiflora incarnata - I know it grows rampant in Texas.

I agree with kayjones, it's likely incarnata. Instead of water I'd put it in soil. Keep it lightly moistened and warm. Once it develops a good root system you can plant it in the garden but be careful because it suckers like crazy. Incarnata is one that I've found difficult to propagate from cuttings but easy from suckers. Yours should grow well. If not your neighbor likely will have loads of it coming up. Just dig up another piece.