Hard Evidence

Create a 0/3 blue Crab creature token.
Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Bountiful Landscape

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

Khalni Garden

This land enters tapped.
When this land enters, create a 0/1 green Plant creature token.
{T}: Add {G}.

Forest

Birchlore Rangers

Tap two untapped Elves you control: Add one mana of any color.
Morph {G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Shared Discovery

As an additional cost to cast this spell, tap four untapped creatures you control.
Draw three cards.

Island

Perilous Research

Draw two cards, then sacrifice a permanent.

Vitalize

Quirion Ranger

Return a Forest you control to its owner's hand: Untap target creature. Activate only once each turn.

Timberwatch Elf

{T}: Target creature gets +X/+X until end of turn, where X is the number of Elves on the battlefield.