Plains

Heart Sliver

Spinneret Sliver

Shadow Sliver

All Sliver creatures have shadow. (They can block or be blocked by only creatures with shadow.)

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Island

Predatory Sliver

Swamp

Muscle Sliver

Sinew Sliver

Twisted Landscape

{T}: Add {C}.
{T}, Sacrifice Twisted Landscape: Search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle.
Cycling {B}{R}{G} ({B}{R}{G}, Discard this card: Draw a card.)

Spitting Sliver

Crypt Sliver

All Slivers have "{T}: Regenerate target Sliver."

Winged Sliver

Tranquil Landscape

{T}: Add {C}.
{T}, Sacrifice Tranquil Landscape: Search your library for a basic Forest, Plains, or Island card, put it onto the battlefield tapped, then shuffle.
Cycling {G}{W}{U} ({G}{W}{U}, Discard this card: Draw a card.)

Sidewinder Sliver

All Sliver creatures have flanking. (Whenever a creature without flanking blocks a Sliver, the blocking creature gets -1/-1 until end of turn.)

Sentinel Sliver

Sliver creatures you control have vigilance. (Attacking doesn't cause them to tap.)

Mountain

Horned Sliver

Utopia Sprawl

Enchant Forest
As Utopia Sprawl enters, choose a color.
Whenever enchanted Forest is tapped for mana, its controller adds an additional one mana of the chosen color.

Blur Sliver

Sliver creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Striking Sliver

Sliver creatures you control have first strike. (They deal combat damage before creatures without first strike.)

Sheltering Landscape

{T}: Add {C}.
{T}, Sacrifice Sheltering Landscape: Search your library for a basic Mountain, Forest, or Plains card, put it onto the battlefield tapped, then shuffle.
Cycling {R}{G}{W} ({R}{G}{W}, Discard this card: Draw a card.)