Rosemary (Rosmarinus officinalis) is a woody, perennial herb with fragrant evergreen needle-like leaves. It is native to the Mediterranean region. It is a member of the mint family Lamiaceae, which also includes many other herbs.
The name rosemary has nothing to do with the rose or the name Mary, but derives from the Latin name rosmarinus, which literally means "dew of the sea", though some think this too may be derived from an earlier name.
The leaves are evergreen, long and 2-5 mm broad, green above, and white below with dense short woolly hairs.
The flowers are variable in color, being white, pink, purple, or blue.
Rosemary is easily pruned into shapes and has been used for topiary. When grown in pots, it is best kept trimmed to stop it getting too straggly and unsightly, though when grown in a garden, rosemary can grow quite large and still be attractive. It can be propagated from an existing plant by clipping a shoot long, stripping a few leaves from the bottom, and planting it directly into soil.
Rosemary has a very old reputation for improving memory, and has been used as a symbol for remembrance (during weddings, war commemorations and funerals) in Europe, probably as a result of this reputation. Mourners would throw it into graves as a symbol of remembrance for the dead. In Shakespeare's Hamlet, Ophelia says, "There's rosemary, that's for remembrance." (Hamlet, iv. 5.) One modern study lends some credence to this reputation. When the smell of rosemary was pumped into cubicles where people were working, those people showed improved memory, though with slower recall.
Another study indicated that carnosic acid, found in rosemary, may shield the brain from free radicals, lowering the risk of strokes and neurodegenerative diseases like Alzheimer's and Lou Gehrig's.
Rosemary contains a number of potentially biologically active compounds, including antioxidants such as carnosic acid and rosmarinic acid. Other bioactive compounds include caffeic acid, ursolic acid, betulinic acid, rosmaridiphenol, and rosmanol.
Health Precautions: Rosemary in culinary or therapeutic doses is generally safe; however, precaution is necessary for those displaying allergic reaction or prone to epileptic seizures. Rosemary essential oil may have epileptogenic properties, as a handful of case reports over the past century have linked its use with seizures in otherwise healthy adults or children. Rosemary essential oil is potentially toxic if ingested. Large quantities of rosemary leaves can cause adverse reactions, such as coma, spasm, vomiting, and pulmonary edema (fluid in the lungs) that can be fatal. Avoid consuming large quantities of rosemary if pregnant or breastfeeding.
Rosemary may also be useful in the prevention and treatment of headlice.