Demonic Foliage

Demonic Foliage's power and toughness are each
equal to half the number of lands you control
rounded up.
The first time you would tap a land for mana each turn, add double that amount of mana instead.
When Demonic Foliage dies, you may return it
to the battlefield tapped as a colorless land with
"{t} Add {g} to your mana pool" and looses all
other card types.