Because the Law of Harvest strictly forbids the continent from shedding traditional mortal blood, the earth instead translates dark or volatile thoughts into dangerous, predatory plants:
Rage-Thorns: These carnivorous, obsidian-black briars are completely blind and dormant if a party travels through the wilderness in quiet, calm introspection. However, they hunt by sensing the heat-vibrations of anger. If two players begin to argue loudly or a combat roll goes poorly, the briars will violently animate, shooting out of the dirt to wrap around the ankles of the angriest character to drain their vitality.
Sorrow-Weepers: These towering, willow-like entities are born when a traveler dies while gripped by absolute, unresolved despair. The tree drinks up the final, tragic thoughts of the dying creature. Anyone who walks within the tree's fog-shrouded canopy must succeed on a Wisdom saving throw or be completely overwhelmed by the dead traveler's memories, falling to their knees in uncontrollable weeping while the mossy soil beneath them turns into quicksand.