Wyroot can be used to construct any melee weapon made entirely of wood or a melee weapon with a wooden haft.
So, I've always believed this wording for Wyroot meant that the weapon had to be completely wooden or have a long wooden grip that make up a large portion of the weapon. Like a polearm or spear, maybe a mace or axe.
However, if you want to get technical, even a sword has a "wooden haft" since a haft is defined as the handle of a weapon or tool. Does this mean any weapon with a wooden grip can be Wyroot? That's a quite a lot of weapons.
I'm inclined to say no, the wording seems like it was intended to limit weapons made with very little wood. I'd like to know how others feel about this.
The few places the rules talk about hafted weapons it talks about weapons like spears (e.g, primarily made of wood, with a possibly metal or bone or stone tip).
RAI is almost certainly only those weapons that are polearm/spear like.
RAW doesn't seem to really specify.
So...the likelihood of a wyroot bow is highly improbable?
This has been discussed before but it's a subtopic on this thread. Bbangerter you are mostly correct in that it's not specifically called out what hafted means, but Table 7-12 Common Armor and Shield Hardness and Hit Points gives a pretty strong indication that bladed weapons should be out based on the rules. And sorry Grizzly, but I don't see bows being in there either.