Piece of the World Tree

There are rumors of a piece of the World Tree (Yggdrasil) that a woman once carved into a walking stick... or bent into a bow... or perhaps used as the foundation of a ship that could travel all the seas in this world... and those beyond. The rumors surrounding its powers are as many as those that have heard of it - shouldn't be too hard to find, though - it's not like there are an awful lot of ash trees around here.