Splinter Wood

  You cause a wooden object, including trees, of Medium size or smaller to violently explode. All creatures within 30 feet must make a Dexterity saving throw. A creature takes 3d6 piercing damage on a failed saving throw, or half as much on a successful one. If the wooden object is held by a creature (such as a spear or quarterstaff), the creature who is holding it may not attempt a saving throw to avoid damage, but must make a Constitution saving throw or be blinded for 1 minute due to flying splinters (if the creature is wearing something over its eyes, such as a full face helmet or similar, it is immune).   Appears in the Complete Tome of Spells