Berries currently come in 8 different colors and variations, and more hunger-reducing berries become available at level 2 of the foraging skill. When foraged, each variation of berry will stack under the same display name of Berries. However, each variation of berry will count as a new and separate ingredient for bonuses in cakes.
As of Build 33 all foraged berries have a chance of being poisonous. The only way to tell if the berries are poisonous is to have picked up the botanist trait during character creation or have read The Herbalist magazine. This will change the display name to Poisonous Berry with a poisonous icon . Just like every other berry, poison ivy berries are not always poisonous.
All berries when fully consumed either provide -5 or -10 hunger and -1 thirst if fresh.