Rosemary is a Mediterranean shrub with needle-like leaves and a distinctive scent. Rosemary oil is the oil extracted from the twigs and fresh leaves of the rosemary plant. People have used rosemary in various forms for centuries, both in folk remedies and to flavor food. Rosemary has medicinal as well as calming properties. Recent studies show that rosemary in different forms can curb inflammation, boost memory, and soothe anxiety. It is also inexpensive and non-toxic.