Sleeper's Grove

When Sleeper's Grove enters the battlefield, it doesn't untap during your next untap step.
{t}: Add {g} or {w} to your mana pool.
The Ilkayan people have always been split between
two worlds. Their cities may seem modest in comparison to some of the grandiose architectures of other nations, but then what need have they of lavish constructions when they can enter a place of imagination made tangible?