All plants referred to as "sage" typically belong to the genus *Salvia*, a massive group within the mint family, Lamiaceae. This family is characterized by square stems, opposite leaves, and aromatic properties due to the presence of essential oils. The most widely known culinary species is *Salvia officinalis*, commonly known as Common Garden Sage. It is a perennial, evergreen subshrub native to the Mediterranean region, prized for its earthy, peppery flavor and gray-green leaves.
Common Sage is the standard culinary variety. Its leaves are oblong, textured with a pebbly or veiny surface, and covered in fine, downy hairs that give them a soft, gray-green appearance. The plant grows into a woody-based, branching shrub reaching up to 2 feet tall and wide. It produces bluish-purple flower spikes in late spring or early summer. Beyond its culinary use, it contains compounds like thujone and camphor, which contribute to its strong aroma and medicinal history. Numerous cultivars have been developed from this species, including dwarf forms and those with variegated foliage.
Purple Sage is not a separate species but a cultivated variety (cultivar) of Common Sage. Its botanical name is *Salvia officinalis* 'Purpurascens'. The primary difference lies in its striking foliage coloration. Its new leaves emerge with a vibrant purple hue, which often matures to a gray-green suffused with purple or deep burgundy, especially in full sun and well-drained soil. The intensity of the purple color can vary with the season and growing conditions. It shares the same growth habit, flower color, and culinary properties as the common green type, though some growers note a slightly milder flavor. It is often planted as much for its ornamental value in gardens as for its culinary use.
The genus *Salvia* encompasses over 900 species, many with distinct characteristics. Three-Group Sage (*Salvia fruticosa*), often sold as "Greek Sage," is a close relative with thinner, woolier leaves and a potentially higher concentration of essential oils. Clary Sage (*Salvia sclarea*) is a biennial species known for its very large, fuzzy leaves and tall flower spikes, grown primarily for aromatic and essential oil production, not cooking. Pineapple Sage (*Salvia elegans*) is renowned for its bright red flowers and leaves that emit a distinct, sweet pineapple fragrance when crushed, used in teas and fruit salads. Finally, the vibrant red annuals often called "Scarlet Sage" belong to *Salvia splendens*, a species valued solely for ornamental bedding displays and not for consumption.
