I finally found it online! "P. incarnata alba."

"Kat" wrote in message
...
While in the woods today I came upon a clump of wild passion flowers.
Nothing at all strange about that here, except that one vine had pure
white
blooms, instead of the common purple/lavender. Never seen this before. Is
it fairly common? I've put a picture of one of the white blooms on
alt.binaries.pictures.gardens , if anyone is interested.