Okay, so in the version I've got, there's a brief moment where Bono is talking about how the song came about. He mentions, how the Rose is a symbol of love in Ireland. Is he talking about the Rose of Tralee/ Mary O'Connor? Or something else? I should probably know being Irish Australian, but that's the first thing I thought of. I've been meaning to ask for months, only I keep forgetting.
EDIT: He says (and I'm not sure if this is exact) "This is based on a time I spent in a hotel called the Million Dollar Hotel in Los Angeles. Which is downtown Los Angeles, its like a half way house hotel for bums and people thrown out of hospitals under the Regan era. And I was being taken through this hotel I was doing some filming down there and I noticed that the cheap liqour all the bums drank was called 'Wild Irish Rose'. So I started with the line 'the city of angels has brought a devil out in me' and developed it on from there. The rose in Ireland is you know, a sort of romantic image of love, obviously. But it's also an image of Ireland itself and that's an image I thought would be nice to subvert."
EDIT2: Just to clarify. There's a festival held in Ireland every year (2nd only to Eurovision in size) called the Rose of Tralee. It's not about Rose bushes either. Story of Mary O'Connor and William Mulchinock