Are rowan tree berries poisonous?

Raw rowan tree berries are poisonous as they contain parasorbic acid. However, if they are cooked well, the parasorbic acid turns into sorbic acid, which is not poisonous to ingest.

The rowan tree, or Sorbus aucuparia, is a fast-growing tree with red berries that grows plentifully in Europe, Africa and Asia. It is a small tree that has gray-brown bark and compound leaves. The flowers on a rowan are sweet-smelling and creamy white in color. The sweet scent of the blooms attracts many flying insects. Along with oak and birch trees, rowan trees are very common in the Caledonian forest region.