Natural Affinity
Instant
All lands become 2/2 creatures until end of turn. They're still lands.
As long as the dryads are a part of the forest, the forest is a part of the army.
イラスト：
Ninth Edition#256★レア英語適正
裁定
2008年8月1日
A noncreature permanent that turns into a creature can attack, and its 
abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn’t matter how long the permanent has been a creature.