3rd-level Transmutation
Casting Time: 1 action
Range: Touch
Components: VSM (a briar vine)
Duration: 10 minutes

You or a creature you touch has sharp briars sprout from their flesh or clothing. You can end the spell early by using an action to dismiss it.
Whenever a creature touches the target or hits it with a melee attack while within 5 feet of it, the sharp briars deal 1d6 piercing damage to that creature. Until the creature regains at least 1 hit point, its walking speed is reduced by 10 feet.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage the attacker takes increases by 1d6 for each slot level above 3rd.

Source: Homebrew