Wave of Rot

Necromantic energy comes out of your hand in the form of a 15ft wave. Creatures in range must make a DEX saving throw. On a failure, the creature takes 6d8 damage. On a success, it takes half damage.

Undead are instead stunned, constructs are uneffected

If you target a plant creature or a magical plant, it makes the saving throw with disadvantage, and the spell deals maximum damage to it.

If you target a nonmagical plant that isn't a creature, such as a tree or shrub, it doesn't make a saving throw; it simply withers and dies.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for each slot level above 3rd.