Salvia officinalis (sage, also called garden sage, common sage, or culinary sage) is a perennial, evergreen subshrub, with woody stems, grayish leaves, and blue to purplish flowers. It is a member of the mint family Lamiaceae and native to the Mediterranean region, though it has naturalized in many places throughout the world. It has a long history of medicinal and culinary use, and in modern times as an ornamental garden plant. The common name "sage" is also used for a number of related and unrelated species.
Salvia officinalis has numerous common names. Some of the best-known are sage, common sage, garden sage, golden sage, kitchen sage, true sage, culinary sage, Dalmatian sage, and broadleaf sage. Cultivated forms include purple sage and red sage. The specific epithet officinalis refers to plants with a well-established medicinal or culinary value.
The plant had a high reputation throughout the Middle Ages, with many sayings referring to its healing properties and value. It was sometimes called S. salvatrix (sage the savior). Dioscorides, Pliny, and Galen all recommended sage as a diuretic, hemostatic, emmenagogue, and tonic. Le Menagier de Paris, in addition to recommending cold sage soup and sage sauce for poultry, recommends infusion of sage for washing hands at table. John Gerard's Herball (1597) states that sage "is singularly good for the head and brain, it quickeneth the senses and memory, strengtheneth the sinews, restoreth health to those that have the palsy, and taketh away shakey trembling of the members." Gervase Markham's The English Huswife (1615) gives a recipe for a tooth-powder of sage and salt. It appears in recipes for Four Thieves Vinegar, a blend of herbs which was supposed to ward off the plague. In past centuries, it was also used for hair care, insect bites and wasp stings, nervous conditions, mental conditions, oral preparations for inflammation of the mouth, tongue and throat, and also to reduce fevers.
Common sage is grown in parts of Europe for distillation of an essential oil, although other species such as Salvia fruticosa may also be harvested and distilled with it. The essential oil contains cineole, borneol, and thujone. Sage leaf contains tannic acid, oleic acid, ursonic acid, ursolic acid, carnosol, carnosic acid, fumaric acid, chlorogenic acid, caffeic acid, niacin, nicotinamide, flavones, flavonoid glycosides, and estrogenic substances.
Some research has suggested certain extracts of salvia officinalis may have positive effects on human brain function, but due to significant methodological problems, no firm conclusions can be drawn. The thujone present in Salvia extracts may be neurotoxic.
In favorable conditions in the garden, S. officinalis can grow to a substantial size (1 square metre or more), but a number of cultivars are more compact. As such they are valued as small ornamental flowering shrubs, rather than for their herbal properties. Some provide low ground cover, especially in sunny dry environments. Like many herbs they can be killed by a cold wet winter, especially if the soil is not well drained. But they are easily propagated from summer cuttings, and some cultivars are produced from seeds.