Go to black city and gain people from pokemon white's white forest who gives you the option of selling leaf stone. After, save, go to the market that just appeared in your city and buy (expensive) leaf stones.
a grass Pokemon
Pansage will evolve by using a Leaf Stone into Simisage.
The only Unova Pokemon that evolves with a Leaf Stone is Pansage.
pansage
route 6
hm im not sure
give it a leaf stone
you can get it by going to route 119 at the tall grass
gloom and nuzleaf to shifery
catch an eevee and use a leaf stone on it
Pansage
use a leaf stone on it