Your missile takes root in the target, sprouting creeping vines that cause the target to stumble and fall.

Encounter   ✦     Primal, Weapon
Standard Action      Ranged weapon

Target: One creature

Attack: Wisdom vs. AC

Hit: 2[W] + 2d6 + Wisdom modifier damage, and the target is slowed until the start of your next turn. The first time the target takes damage while slowed by this power, the target is instead immobilized until the end of your next turn. The first time the target takes damage while immobilized by this power, the target falls prone.

Published in Player's Handbook 3, page(s) 128.