It's difficult to say. There is much that we've forgotten about our heritage; it's the price paid for integration, I suppose. Though I hesitate to use that term, as city elves are most definitely not given the same rights and treatment as others. Back to the subject, I believe it is often an oak due to the constellation Fervanis, which is also known as 'the oak'. Some believe it was originally a constellation of the elven people, before Tevinter claimed it.

Being a Warden is one reason, yes. My duties naturally keep me elsewhere; there aren't darkspawn to be found in alienages, typically. I am -was- a Circle mage, as well. When we are discovered to possess magic, mages are taken to Circle towers to learn, and there we remain unless there is a good reason and official sanction to depart. Or at least that was true until rather recently. The tower was my home for most of my life, so those I know best are, if not from the order, from the Circle. I doubt any in the alienage remember me.

[Her tone isn't self-pitying or bitter. It is what it is, and she's come to terms with that long ago.]