I've long wondered about the significance of the name of Master Ash and his cryptic reference to Vine.
I've found one likely reference in Norse mythology, in which the first man and woman were named Ask and Embla, which translate in English to ash tree and elm tree, but alternatively Embla can be vine or liana. http://en.wikipedia.org/wiki/Ask_and_Embla
Given Ash's association with Ragnarok, Norse seems like a likely source.
But I just bumped into a tantalizing alternative. One of the most ancient Egyptian gods was named Ash, and as god of the desert oases, he was also the god of the vine. As a desert god he was also associated (sometimes sexually) with Typhon Set, the god of desert storms.
I guess I still think the Norse inspiration is mostly likely the primary one. But it is hard to dismiss a nominative clue which relates to both Typhon and The Outsider/Dionysus.