Unstoppable Ash

Trample
Champion a Treefolk or Warrior (When this enters the battlefield, sacrifice it unless you exile another Treefolk or Warrior you control. When this leaves the battlefield, that card returns to the battlefield.)
Whenever a creature you control becomes blocked, it gets +0/+5 until end of turn.

Cathar's Shield

Equipped creature gets +0/+3 and has vigilance.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Dawn

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Return all creature cards with power 2 or less from your graveyard to your hand.

Dusk

Destroy all creatures with power 3 or greater.

Dusk // Dawn

Fell the Mighty

Destroy all creatures with power greater than target creature's power.

Treebeard, Gracious Host

Trample, ward {2}
When Treebeard, Gracious Host enters the battlefield, create two Food tokens.
Whenever you gain life, put that many +1/+1 counters on target Halfling or Treefolk.

Accorder's Shield

Equipped creature gets +0/+3 and has vigilance. (Attacking doesn't cause it to tap.)
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Arcane Signet

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

Indomitable Ancients

Treefolk Harbinger

When Treefolk Harbinger enters the battlefield, you may search your library for a Treefolk or Forest card, reveal it, then shuffle and put that card on top.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Warden of the Woods

Vigilance (Attacking doesn't cause this creature to tap.)
Whenever Warden of the Woods becomes the target of a spell or ability an opponent controls, you may draw two cards.

Doran, the Siege Tower

Each creature assigns combat damage equal to its toughness rather than its power.

Last March of the Ents

This spell can't be countered.
Draw cards equal to the greatest toughness among creatures you control, then put any number of creature cards from your hand onto the battlefield.

Rampant Growth

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

Treefolk Umbra

Enchant creature
Enchanted creature gets +0/+2 and assigns combat damage equal to its toughness rather than its power.
Totem armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Yedora, Grave Gardener

Whenever another nontoken creature you control dies, you may return it to the battlefield face down under its owner's control. It's a Forest land. (It has no other types or abilities.)

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with Tree of Perdition's toughness.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Tower Defense

Creatures you control get +0/+5 and gain reach until end of turn.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Refuse to Yield

Target creature gets +2/+7 until end of turn. Untap it.

Bosk Banneret

Treefolk spells and Shaman spells you cast cost {1} less to cast.

Spidersilk Net

Equipped creature gets +0/+2 and has reach. (It can block creatures with flying.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Slagwurm Armor

Equipped creature gets +0/+6.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters the battlefield unattached and stays on the battlefield if the creature leaves.)

Explosive Vegetation

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

Ulvenwald Observer

Whenever a creature you control with toughness 4 or greater dies, draw a card.

Faeburrow Elder

Vigilance
Faeburrow Elder gets +1/+1 for each color among permanents you control.
{T}: For each color among permanents you control, add one mana of that color.

Rootless Yew

When Rootless Yew dies, search your library for a creature card with power or toughness 6 or greater, reveal it, put it into your hand, then shuffle.

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Rootgrapple

Destroy target noncreature permanent. If you control a Treefolk, draw a card.

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.

Tree of Redemption

Defender
{T}: Exchange your life total with Tree of Redemption's toughness.

Sol Ring

Robe of Stars

Equipped creature gets +0/+3.
Astral Projection — {1}{W}: Equipped creature phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)
Equip {1}

Angelic Chorus

Whenever a creature enters the battlefield under your control, you gain life equal to its toughness.

Timber Protector

Other Treefolk creatures you control get +1/+1.
Other Treefolk and Forests you control have indestructible.

Plains

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.

Bar the Door

Creatures you control get +0/+4 until end of turn.

Everbark Shaman

{T}, Exile a Treefolk card from your graveyard: Search your library for up to two Forest cards, put them onto the battlefield tapped, then shuffle.

Stoneskin

Flash
Enchant creature
Enchanted creature gets +0/+10.

Spidersilk Armor

Creatures you control get +0/+1 and have reach. (They can block creatures with flying.)

Quickbeam, Upstart Ent

Whenever Quickbeam, Upstart Ent or another Treefolk enters the battlefield under your control, up to two target creatures each get +2/+2 and gain trample until end of turn.

Unnatural Growth

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

Nemata, Grove Guardian

{2}{G}: Create a 1/1 green Saproling creature token.
Sacrifice a Saproling: Saproling creatures get +1/+1 until end of turn.

Garruk's Uprising

When Garruk's Uprising enters the battlefield, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (They can deal excess combat damage to the player or planeswalker they're attacking.)
Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.

Aegis of the Heavens

Target creature gets +1/+7 until end of turn.

Black Poplar Shaman

Kodama's Reach

Nemata, Primeval Warden

Reach
If a creature an opponent controls would die, exile it instead. When you do, create a 1/1 green Saproling creature token.
{G}, Sacrifice a Saproling: Nemata, Primeval Warden gets +2/+2 until end of turn.
{1}{B}, Sacrifice two Saprolings: Draw a card.

Ezzaroot Channeler

Reach
Creature spells you cast cost {X} less to cast, where X is the amount of life you gained this turn.
{T}: You gain 2 life.

Reach of Branches

Create a 2/5 green Treefolk Shaman creature token.
Whenever a Forest enters the battlefield under your control, you may return Reach of Branches from your graveyard to your hand.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Swamp

Verdeloth the Ancient

Kicker {X} (You may pay an additional {X} as you cast this spell.)
Saproling creatures and other Treefolk creatures get +1/+1.
When Verdeloth the Ancient enters the battlefield, if it was kicked, create X 1/1 green Saproling creature tokens.

Assemble the Entmoot

Creatures you control have reach.
Sacrifice Assemble the Entmoot: Create three tapped X/X green Treefolk creature tokens, where X is the amount of life you gained this turn. Put a reach counter on each of them.

Colfenor, the Last Yew

Vigilance, reach
Whenever Colfenor, the Last Yew or another creature you control dies, return up to one other target creature card with lesser toughness from your graveyard to your hand.

Fangorn, Tree Shepherd

Treefolk you control have vigilance.
Whenever one or more Treefolk you control attack, add twice that much {G}.
You don't lose unspent green mana as steps and phases end.

Belbe's Armor

{X}, {T}: Target creature gets -X/+X until end of turn.

Forest

Sapling of Colfenor

Indestructible
Whenever Sapling of Colfenor attacks, reveal the top card of your library. If it's a creature card, you gain life equal to that card's toughness, lose life equal to its power, then put it into your hand.

Lignify

Enchant creature
Enchanted creature is a Treefolk with base power and toughness 0/4 and loses all abilities.

Up the Beanstalk

When Up the Beanstalk enters the battlefield and whenever you cast a spell with mana value 5 or greater, draw a card.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.