Acorns

Acorns is a quest item. It can be obtained from the duergar Ilyich in Irenicus' Dungeon. After talking to the imprisoned dryads, the acorn needs to be brought to the dryad in the Windspear Hills, near the house of Garren Windspear.

In-game description
"These are the dryads' magical acorns that you've obtained off of the duergar leader, Ilyich."