Whatever the proper name, I love this plant. The vine blooms most of the year, although being tropical it tends to preform best in warm weather. Due to the red and veiny nature of the flower I have anatomical references; the unopened flower looks like a liver (maybe life size) and the open flower is like a frontal section of the lungs. It definitely attracts attention, people are drawn to its strangeness and sheer size. The flowers feel like latex, and the unopened flower is inflated which is fun too. The Fullerton Arboretum has a huge plant that probably spans more than 200' growing on a chain link fence. At the moment I have only upsized the vine to a 15 gallon container but I plan to plant it soon on the wall of the garage.
Pretty cool, right?