Leyline of Abundance

If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield.
Whenever you tap a creature for mana, add an additional {G}.
{6}{G}{G}: Put a +1/+1 counter on each creature you control.

Mountain

Fyndhorn Elves

Elvish Mystic

Llanowar Elves

Llanowar Loamspeaker

{T}: Add one mana of any color.
{T}: Target land you control becomes a 3/3 Elemental creature with haste until end of turn. It's still a land. Activate only as a sorcery.

Priest of Titania

{T}: Add {G} for each Elf on the battlefield.

Marwyn, the Nurturer

Whenever another Elf you control enters, put a +1/+1 counter on Marwyn, the Nurturer.
{T}: Add an amount of {G} equal to Marwyn's power.

Radha, Heir to Keld

Whenever Radha, Heir to Keld attacks, you may add {R}{R}.
{T}: Add {G}.

Raggadragga, Goreguts Boss

Each creature you control with a mana ability gets +2/+2.
Whenever a creature you control with a mana ability attacks, untap it.
Whenever you cast a spell, if at least seven mana was spent to cast it, untap target creature. It gets +7/+7 and gains trample until end of turn.

Llanowar Tribe

Elvish Archdruid

Other Elf creatures you control get +1/+1.
{T}: Add {G} for each Elf you control.

Forest

Circle of Dreams Druid

{T}: Add {G} for each creature you control.

Paradise Druid

This creature has hexproof as long as it's untapped. (It can't be the target of spells or abilities your opponents control.)
{T}: Add one mana of any color.

Quirion Elves

As Quirion Elves enters, choose a color.
{T}: Add {G}.
{T}: Add one mana of the chosen color.