Grass-Wastes
Land (Rare)

Grass-Wastes enters the battlefield tapped unless you control five or more artifact lands.

Tap: Add G or U to your mana pool.

Put Grass-Wastes on top of your library: Add 1 to your mana pool.

1GU, Tap: Exile target basic land, then return it to the battlefield under its owner's control.

Steve Chan