Entangle

By means of this spell the druid is able to cause plants in the area of effect to entangle creatures within the area. 

The grasses, weeds, bushes, and even trees wrap, twist, and entwine about creatures, thus holding them fast for the duration of the spell. If any creature in the area of effect makes its saving throw, the effect of the spell is to slow its movement by 50% for the spell duration.