Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Wandering Stream

Domain — You gain 2 life for each basic land type among lands you control.

Molimo, Maro-Sorcerer

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Molimo's power and toughness are each equal to the number of lands you control.

Strength of Unity

Enchant creature
Domain — Enchanted creature gets +1/+1 for each basic land type among lands you control.

Quirion Trailblazer

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Exotic Curse

Enchant creature
Domain — Enchanted creature gets -1/-1 for each basic land type among lands you control.

Magnigoth Treefolk

Domain — For each basic land type among lands you control, this creature has landwalk of that type. (It can't be blocked as long as defending player controls a land of that type.)

Quirion Dryad

Whenever you cast a spell that's white, blue, black, or red, put a +1/+1 counter on this creature.