Enter the Unknown

Target creature you control explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)
You may play an additional land this turn.

Manamorphose

Add two mana in any combination of colors.
Draw a card.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Llanowar Visionary

When Llanowar Visionary enters, draw a card.
{T}: Add {G}.

City of Traitors

When you play another land, sacrifice City of Traitors.
{T}: Add {C}{C}.

Elvish Spirit Guide

Exile Elvish Spirit Guide from your hand: Add {G}.

Forest

Edge of Autumn

If you control four or fewer lands, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Cycling—Sacrifice a land. (Sacrifice a land, Discard this card: Draw a card.)

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Emerald Medallion

Green spells you cast cost {1} less to cast.

Concordant Crossroads

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Explore

You may play an additional land this turn.
Draw a card.

Dryad Arbor

(Dryad Arbor isn't a spell, it's affected by summoning sickness, and it has "{T}: Add {G}.")

Green Sun's Zenith

Search your library for a green creature card with mana value X or less, put it onto the battlefield, then shuffle. Shuffle Green Sun's Zenith into its owner's library.