White berries are secondary herblaw ingredients that spawn in level 36 and 39 wilderness in the south-eastern Red Dragon Isle. They also are dropped by Chaos Druid Warriors and Salarin the Twisted.
The respawn rate of the berries is fast, it takes only 30 seconds to spawn in an empty server. Thus it is more efficient to pick one spawn than two, unless Telekinetic grab is used.
These are a fantastic way to make money. They are used to make regular and Super Defense Potions at level 30 and 66 herblaw, so high-level herbalists will buy them for many coins each.