Harir

This plant, which leaves similar to holly but much less thick, grows at altitude. The consumption of its infusion which mixes its leaves and its acorns hardens the epidermis after a delay of 10 minutes.
An infusion of harir reduces bludgeoning, piercing, and slashing damage you take from nonmagical weapons by 1 for 10 minutes. Several doses do not accumulate the bonus, but in some mountain dwellers who have consumed it regularly for years, the effect would become permanent.