You can receive a Leaf Stone in Pokémon SoulSilver by winning first place in the National Park Bug Catching Contest, receiving one from a trainer in Route 34 after receiving a PokéGear Phone call, finding one in the Viridian City and then you can also receive one by receiving one from Bill's Grandfather in Route 25 after you have showed him an Oddish, the Leaf Stone will evolve Exeggcute into Exeggutor, Gloom into Vileplume, Pansage into Simisage, Weepinbell into Victreebel and Nuzleaf into Shiftry.
use a leaf stone
You can evolve Gloom by a sun stone, or a Leaf stone. Sun stone= Belossom Leaf stone= Vileplume
in Viridian Forest looks like a pokeball
Get a Leaf Stone and you'll evolve it.
In order of how he wants to see them (based on Heart Gold and Soul Silver): Gold/Heart Gold: Oddish - Leaf Stone Growlithe - Fire Stone Pichu - Thunderstone Jigglypuff - Everstone Marill - Water Stone Silver/Soul Silver: Lickitung - Everstone Oddish - Leaf Stone Staryu - Water Stone Vulpix - Fire Stone Pichu - Thunderstone
At the pokemoncontatholon
The leaf stone is used to evolve certain poke'mon.
seven
use a leaf stone
You can evolve Gloom by a sun stone, or a Leaf stone. Sun stone= Belossom Leaf stone= Vileplume
in Viridian Forest looks like a pokeball
weepinbell, and eevee if you trade. :)
Get a Leaf Stone and you'll evolve it.
Level it to 14 then give it a Leaf Stone
weepinbell evolves by either the leaf stone, or the sun stone.
Pokethlon Dome, costs 2500 athlete points
"A stone that can be used to evolve Gloom, Weepinbell, Exeggcute, Nuzleaf and Eevee (Leafeon)"Serebii.net - Item - Leaf Stone (Platinum)