Rosemary (Rosmarinus officinalis)

Rosmarinus officinalis, commonly known as rosemary, is a woody, perennial herb with fragrant, evergreen, needle-like leaves and white, pink, purple, or blue flowers, native to the Mediterranean region.

Rosemary is in the same taxonomic family as mint, but doesn't have the same characteristic flavor. It has a warmer, bitter, and more astringent taste that gives a wonderful flavor to soups, sauces, stews, roasts, and stuffing. It is particularly prevalent in Italian cultural cuisine. It is also commonly used in natural healing practices, as rosmarinic oil and other active ingredients in this herb can be very helpful for a number of health issues.Although small amounts like those used to flavor food aren’t typically considered large enough to have a major effect on the body, regular addition of the leaves to your food will allow your body to derive accumulated benefits from the organic compounds and unique phytochemicals present in the leaves.

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There are also uses of rosemary that involve consuming larger quantities or applying the essential oils from rosemary onto the skin directly.
Its reputation as a memory enhancer stems from ancient Greece where students wore garlands of rosemary in the belief it would help their memory, rather than studying all night. To this day, students in Greece, who are about to take exams, burn it in their homes.
In times past, rosemary was burned in sick chambers to purify the air. Branches were strewn in courts of law as a protection from “jail fever” (typhus).
Throughout history, herbalists and traditional healers have recommended rosemary to cure baldness, and paralysis, improve memory, treat depression and headaches, and heal bruises and skin wounds. In edition to be rich in antioxidant, carnosol one of the components in rosemary, is also known for its anti-cancer & anti inflamatory properties, which can help explain why rosemary essential oil is so potent.
Some of the benefits: it improves memory,promotes hair growth, detox the liver and gallbladder and enhance their function, it lowers cortisol levels to protect the body from oxidative stress.
Ref.
Dr Axe website