Where are the Herbs of White?

[BoltBlades12]

I'm seeking white herbs so that I can craft pp maxes. I know I can get them via bp at the frontier/subway, but that gets a bit tedious especially on the higher levels. Does anybody know if there's a location where I can get white herbs via pickup or via wild pokemon holding white herb and where?

[Lin]

In addition to the above, you can also obtain Battle Points from completing the E4 and it’s subsequent rematches and from unranked/ ranked matchmaking.