Willow of Wisps

{t}Add {g}{g} to your mana pool. Willow of Wisps
does not untap during your next untap step.
{t}Create two 1/1 white and green Wisp tokens.
{0}: Until end of turn all wisps gain +X/+X,
where X is the number of forests you control.
Willow of Wisps phases out.
The tiny energy beings hid near the magical tree that birthed them, unless called away by a greater power.