Rosmarinus officinalis (rosemary)
Rosmarinus officinalis flower (Photo: Wolfgang Stuppy)
Rosmarinus officinalis L.
Dry scrub land in the Mediterranean region, but widely cultivated.
Culinary herb, medicinal, symbol of remembrance, ornamental.
The essential oil of rosemary is potent and should be avoided by pregnant and breastfeeding women. The oil may cause severe adverse effects including seizures when taken internally and may irritate the skin when applied externally.
About this species
Rosemary belongs to the Lamiaceae, commonly known as the mint family. It is related to other well-known herbs such as the basils (Ocimum), thymes (Thymus) and mints (Mentha), but its closest relative is the genus Salvia, which includes at least 900 species. One of these is sage (Salvia officinalis). Many scientists believe that rosemary is so similar to Salvia that it should be included in this group. Salvia and rosemary both have only two stamens (male organs of the flower, containing pollen), whereas in the mint family the usual number of stamens is four.
In the past, rosemary was believed to aid memory and was often made into garlands for students when they were sitting their exams. Scientific research has shown that rosmarinic acid, one of the main constituents of rosemary, inhibits certain enzymes linked to neurological disorders causing memory loss. Scientists at Kew investigating the benefits of rosmarinic acid found it has strong anti-oxidant properties.
Preparations of rosemary are taken orally or applied topically for a variety of complaints. The leaves and flowers can also be used to make a tea, said to be good for headaches, colic, colds and nervous diseases as well as depression. Rosemary has also been used in herbal remedies for relieving asthma. Used in combination with essential oils from thyme (Thymus), lavender (Lavandula) and cedarwood (Cedrus), the essential oil of rosemary reportedly improves hair growth in people with allopecia. It also has antibacterial and antifungal properties. There is evidence that the essential oil relaxes the muscles of the gastrointestinal tract, and may increase blood flow to the heart. However, the essential oil of rosemary is potent and can be toxic. It should be avoided by pregnant and breastfeeding women, and by people prone to seizures.