Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Mountain

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Forest

Zacama, Primal Calamity

Vigilance, reach, trample
When Zacama, Primal Calamity enters, if you cast it, untap all lands you control.
{2}{R}: Zacama deals 3 damage to target creature.
{2}{G}: Destroy target artifact or enchantment.
{2}{W}: You gain 3 life.