According to Wikipedia, Hickory is a tree native from America and East Asia. But it is listed in the Houses of Hermes: Mystery Cults p137 as one of the Shape & Form bonuses available?
Is there any way in which that tree could be known and accessed by 1220 year Order of Hermes magi?
I suppose it could come along the Silk Road from China or India, so a PC may most reasonably acquire it in the Levant Tribunal, or Constantinople, or Venice. That gives the GM the perfect excuse to make it as rare and valuable as they like, or hang a story off its acquisition.
Ooohhhh, that's a pitty. Damn interesting bonuses for a type of wood. Logical, though.