10/1/2007: Lignify overwrites characteristic-defining abilities that specify the enchanted creature's power or toughness (such as the one Dauntless Dourbark has) or that specify its creature types (such as changeling does).
10/1/2007: Lignify overwrite any previous effects that set the enchanted creature's power or toughness (such as Serendib Sorcerer does) as well as any previous effects from resolved spells and abilities that changed the enchanted creature's power or toughness (such as Giant Growth). Any such effects that apply after Lignify came into play will work normally.
10/1/2007: Lignify doesn't overwrite changes to the enchanted creature's power or toughness that come from counters or from static abilities from other sources (such as Glorious Anthem). It will overwrite static abilities that come from the creature itself (such as the one on Verduran Enchantress) because Lignify causes the creature to lose that ability before it gets a chance to apply.
10/1/2007: Lignify overwrites previous effects that changed the enchanted creature's creature types. Any such effects that apply after Lignify comes into play will work normally.
10/1/2007: Lignify causes the enchanted creature to lose all abilities it had at the time it became enchanted. Any abilities granted to the creature after Lignify came into play will work normally.
10/1/2007: If a previous effect switched the creature's power and toughness, that effect still applies (though it will apply to the creature's new power and toughness).
10/1/2007: If the enchanted creature has a characteristic-defining ability that specifies its color, that ability will still have its effect because it's applied before the creature loses the ability.
10/1/2007: If Lignify leaves play, the creature goes back to being what it was before. Any effects that applied while the Lignify was in play, such as Giant Growth or Lace with Moonglove, will continue to apply.
Lorwyn
(Common)