Stick is a colloquial term for both framing lumber (timber) and a "timber tree" (a tree trunk good for using as lumber (timber)); thus, the names "stick and platform", "stick and frame", "stick and box", or simply stick framing.
The term "stick" is used interchangeably to refer to both the lumber used for framing structures and the tree from which it comes.  This can be seen in terms like "stick and platform", "stick and frame", "stick and box", or simply "stick framing".