California poppy

It is a psychoactive plant, but not addictive.

An excerpt from the article 17 facts about California poppy

It has been used by indigenous people in California since prehistoric times as a painkiller, sedative, and hypnotic drug. It produces mild psychoactive effects.

Today it is used by many people to treat anxiety and sleep disorders. It is not safe to use the plant without consulting a doctor, as it can be toxic in certain amounts.