Thorns of Silvanus

Channeling the will of Silvanus, the Forest Father, the caster creates circle of thorns made from the energy of nature itself that constantly revolves around either the caster or a target within 15 feet.  When attacked, the thorns will grow into large spikes, forcing the attacker to perform a DEX Saving Throw (Caster's Spell Save DC).  Upon failing said throw, the attacker will suffer 2d8 damage.  

The thorns will last for 3 rounds, or until the caster has been struck two times.  The caster can send the circle of thorns towards another party member at the cost of one bonus action.

When cast at a higher spell level than 3, add 1d8 per spell level.  (For example, at 4th level, it's 3d8, 5 is 4d8, etc.)