I'm afraid they don't. Though, does the absence of scent count? They were created for recycling, and tend to draw things into themselves.

[ He inclines his head at Shirou's next question ]

Hmm... well, I don't suppose you could carpet the area with elemental energy... let me think. [ Forneus turns to a drawer and begins to rummage through it. ] Ordinarily, I wouldn't need to use anything like a dowsing machine - the White Tree is a creation of the gods, after all - but I did pick up a small trinket a couple centuries ago that might have some use.

[ He produces a white stone on a string, and holds it out. ]

This is a piece of White Tree wood, preserved by alchemical methods. It will try to return to its brethren - that is, other White Tree parts, which include seeds. Give it a try.