Cool. FWIW, here are the pertinent bits from the wood element creature template in Manual of the Planes.
Plant Traits: While of the elemental type, a wood element creature is also plantlike. In addition to benefits granted through its elemental type, the wood element creature gains immunity to polymorphing and is not subject to mind-influencing effects (charms, compulsions, phantasms, patterns, and morale effects).
Spikes (Ex): A wood element creature can release volleys of bark, splinters, or wood shards, up to four such spikes per round, as a standard action. This attack has a range of 120 feet with no range increment. Damage is 1d6 + Strength bonus. The wood element creature can launch up to its HD total in spikes per day.
Woodsense (Ex): A wood element creature can automatically sense the location of anything within 60 feet that is in contact with vegetation, even if the wood element creature is not in contact with the same vegetation.