Sol Ring

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Lotus Cobra

Landfall — Whenever a land you control enters, add one mana of any color.

Swamp

Plains

Arcane Signet

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

The Necrobloom

Landfall — Whenever a land you control enters, create a 0/1 green Plant creature token. If you control seven or more lands with different names, create a 2/2 black Zombie creature token instead.
Land cards in your graveyard have dredge 2. (You may return a land card from your graveyard to your hand and mill two cards instead of drawing a card.)