Regenerate

When a regenerate spell is cast, body members (fingers, toes, hands, feet, arms, legs, tails, or even the heads of multi-headed creatures), bones, or organs will grow back. 

The process of regeneration requires but 1 round if the member(s) severed is (are) present and touching the creature, 2-8 turns otherwise.

The reverse, wither, causes the member or organ touched to shrivel and cease functioning in 1 round, dropping off into dust in 2-8 turns. As is usual, creatures must be touched in order to have harmful effect occur. 

The material components of this spell are a prayer device and holy/ unholy water.