Field abilities
Field abilities are actions some Pokémon perform on the map: surfing, flying, cutting trees, smashing rocks... Any living Pokémon in your Pokébar can use them, without leaving its ball. Each one is unlocked by a Gym Badge; before that, an equipped Ability Capsule unlocks them all for 15 minutes. No ability starts during a battle (a wild Pokémon fighting you or your Pokémon, or a trainer battle): finish the fight first. Getting off a mount and putting Flash out are always allowed.
Cut
Cuts down the small trees that block the way.

Unlocked by: Rainbow Badge (Erika, Celadon City)
Bulbasaur
Ivysaur
Venusaur
Oddish
Gloom
Vileplume
Paras
Parasect
Bellsprout
Weepinbell
Victreebel
Exeggcute
Exeggutor
Tangela