- Division: Tracheophyta
- Class: Magnoliopsida
- Order: Lamiales
- Family: Lamiaceae
- Genus: Rosmarinus
- Species: officinalis
It’s one of the world’s favorite herbs and was immortalized in Shakespeare’s Hamlet when Ophelia says, “There’s rosemary, that’s for remembrance.” Shakespeare was referring to an old folk ballad and the traditional belief that rosemary could strengthen memory. As it turns out, these legends contained some truth: scientific studies have found that rosemary can be an effective memory stimulant. As a member of the mint family, rosemary leaves contain oils that produce the plant’s well-known scent. Rosemary oil has also been shown to have antifungal, antibacterial, and antioxidant properties, and it is used in soaps, lotions, and perfumes. But rosemary is most popular as a culinary herb, famous for its flavorful contribution to sauces, soups, stuffings, and spice medleys.
Rosemary is described as a woody, perennial herb that can become a bushy shrub. The leaves are evergreen and needlelike in shape, and they produce the essential oil that gives rosemary its characteristic scent. They are dark green on the upper side, and the underside has a dense covering of short, white, woolly hairs. Some varieties of rosemary grow in an upright form, and stalks can reach five feet tall. Other varieties have a trailing form with the branches curving downward into a cascade effect.
The small flowers of rosemary can be blue, violet, purple, pink, or white, depending on the variety. They are fragrant and attract bees, butterflies, and some birds, which the plant depends on for pollination. In temperate climates the plant flowers in spring and summer, but in warmer areas it can bloom year round.
The essential oil rosemary produces contains camphor and rosmarinic acid. The latter has been shown in scientific studies to inhibit enzymes linked to neurological disorders that cause memory loss. Rosmarinic acid has also been found to have strong antioxidant, antibacterial, and antifungal properties.
Rosemary is cultivated worldwide, and there are more than 24 cultivars of rosemary commonly grown. Some of the varieties that are considered best for cooking are “Blue Spires,” “Tuscan Blue,” and “Gorizia.” There are also two other species of rosemary, Rosmarinus tomentosus and Rosmarinus eriocalyx, but they are less common that Rosmarinus officinalis.
This tough Mediterranean plant needs full sun and light soil that doesn’t become waterlogged. It is adapted to long, hot summers and can withstand periods of drought. New growth is soft and flexible and contains the most oil; older stems become woody and over time can form a substantial shrub trunk.