Blight (5.5e Patch)

A creature that you can see within range makes a Constitution saving throw. On a failed save, the target takes 8d8 Necrotic damage, and can't regain Hit Points until the end of your next turn. During that time, it also temporarily gains 1 level of the Exhaustion condition. On a successful save, the target takes half as much damage only. A Plant creature automatically fails the save.

Alternatively, target a nonmagical plant that isn't a creature, such as a tree or shrub. It doesn't make a save; it simply withers and dies.

Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 4.