By Harold McGee
Juniper berries are not leaves, but their essence is the aroma of pine needles, so I include them here, along with the observation that pine and other evergreen needles are often used as flavorings. The Chinese steam fish over pine needles, and the original flavoring for salt-cured salmon (gravlax) was probably pine needles rather than dill. Pineyness is also one element in the aromas of many herbs and spices (see charts).
There are about 10 species of Juniperus, a distant relative of the pine, all native to the northern hemisphere. They make small cone-like reproductive structures, about a third of an inch or 10 mm across, but the scales remain fleshy and coalesce to form a “berry” that surrounds the seeds. The berries take from one to three years to mature, during which they turn from green to purplish black. When immature, their aroma is dominated by the terpene pinene; when mature, they carry a mix of pine, green-fresh, and citrus notes. After two years in a spice bottle there is very little aroma left: so juniper berries are best when foraged and fresh. They are much used in northern Europe and Scandinavia to flavor meats, especially game, and cabbage dishes. Juniper is the distinguishing flavor in gin, and gave gin its name (originally Dutch genever).