- - Leeches. Maybe in water rooms at an uncommon rarity. Medical uses.
- Flax fibers. It's a cool-climate plant/fiber one might find around Lithmore. Crafting uses.
Foraging takes time and MV, so buying the items will probably still be preferable to it (and keep the economy moving as best it can). Would just be cool to have them available from foraging, where it fits, if you're determined to scour for them and/or ridiculously poor.
It would also be super neat if foraging possibilities were based on the things in the room. For example, in a garden room growing anise and peppercorns, you might be able to find little bits of anise or peppercorn (or much more rarely, seeds). (EDIT: Somebody mentioned this is already the case - Nevermind!)