Slowfoot

Slowfoot is a small cottony flowers herb. It gives a light green liquid which, mixed in the food, increases the rhythm of the breathing and gives a feeling of exhaustion.
A creature subjected to this poison must succeed on a DC 11 Constitution saving throw or his level of exhaustion increases by 1 until the creature finishes a long rest. If the saving throw fails by 5 or more, its level of exhaustion increases by 2 instead of 1.