A first-year flowering, bushy perennial that produces small, tubular flowers, usually deep blue or violet. Hyssop's leaves are narrow, lance-shaped, and dark green. They are about 2.5 to 5 cm long and grow in opposite pairs along the stems. The leaves are aromatic, with a slightly bitter, minty flavor.

The leaves and flowers of hyssop are used as a seasoning in cooking. Its flavor is strong, so it is generally used sparingly. Hyssop has traditionally been used for its expectorant, antiseptic, and anti-inflammatory properties. In large doses, it can be toxic.

The essential oil extracted from hyssop is used in aromatherapy and perfumery. It has a sweet, camphor-like aroma.