The Black Berry is a small harvestable food item.
In its current form, black berries are one of the lowest forms of food production in RUST.
You can harvest each small black berry bush for 1 or 2 berries. Once eaten, you will receive some Black Berry Seeds.
Unfortunately, black berries provide so few calories and hydration as to make them essentially useless.
Unlike other berries, the black berry isn’t used in any tea recipes at the Mixing Table.
As a final insult to the black berry, they are also essentially useless when composted, as each berry will only contribute to 0.01 of a whole piece of Fertilizer.