Case of the Locked Hothouse

You may play an additional land on each of your turns.
To solve — You control seven or more lands. (If unsolved, solve at the beginning of your end step.)
Solved — You may look at the top card of your library any time, and you may play lands and cast creature and enchantment spells from the top of your library.

Sylvan Scrying

Search your library for a land card, reveal it, put it into your hand, then shuffle.

Exploration

You may play an additional land on each of your turns.

Wreck and Rebuild

Choose one —
• Destroy target artifact or enchantment.
• Mill five cards, then you may put a land card from your graveyard onto the battlefield tapped.
Flashback {3}{R}{G}

Hour of Promise

Search your library for up to two land cards, put them onto the battlefield tapped, then shuffle. Then if you control three or more Deserts, create two 2/2 black Zombie creature tokens.

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.

Gruul Signet

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Map the Frontier

Search your library for up to two basic land cards and/or Desert cards, put them onto the battlefield tapped, then shuffle.

Summer Bloom

You may play up to three additional lands this turn.

Selesnya Signet

Explore

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

Boros Signet

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Roiling Regrowth

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

Colossal Rattlewurm

Colossal Rattlewurm has flash as long as you control a Desert.
Trample
{1}{G}, Exile Colossal Rattlewurm from your graveyard: Search your library for a Desert card, put it onto the battlefield tapped, then shuffle.

Shefet Monitor

Cycling {3}{G} ({3}{G}, Discard this card: Draw a card.)
When you cycle Shefet Monitor, you may search your library for a basic land card or a Desert card, put it onto the battlefield, then shuffle. (Do this before you draw.)

Escape to the Wilds

Exile the top five cards of your library. You may play cards exiled this way until the end of your next turn.
You may play an additional land this turn.

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Dance of the Tumbleweeds

Spree (Choose one or more additional costs.)
+ {1} — Search your library for a basic land card or a Desert card, put it onto the battlefield, then shuffle.
+ {3} — Create an X/X green Elemental creature token, where X is the number of lands you control.

Sand Scout

When Sand Scout enters, if an opponent controls more lands than you, search your library for a Desert card, put it onto the battlefield tapped, then shuffle.
Whenever one or more land cards are put into your graveyard from anywhere, create a 1/1 red, green, and white Sand Warrior creature token. This ability triggers only once each turn.

Entish Restoration

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. If you control a creature with power 4 or greater, instead search your library for up to three basic land cards, put them onto the battlefield tapped, then shuffle.

Wayward Swordtooth

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
You may play an additional land on each of your turns.
Wayward Swordtooth can't attack or block unless you have the city's blessing.

Tempt with Discovery

Tempting offer — Search your library for a land card and put it onto the battlefield. Each opponent may search their library for a land card and put it onto the battlefield. For each opponent who searches a library this way, search your library for a land card and put it onto the battlefield. Then each player who searched a library this way shuffles.

Spelunking

When Spelunking enters, draw a card, then you may put a land card from your hand onto the battlefield. If you put a Cave onto the battlefield this way, you gain 4 life.
Lands you control enter untapped.