About Ammi majus L.
Ammi majus L. is a herbaceous plant that is typically annual, though it is actually a biennial that grows as an annual in cultivation. Its lower leaves are 1 to 2-pinnate, while its upper leaves are 2(-3)-pinnate with serrated lobes. It produces flowers in compound umbel inflorescences, which are white and umbrella-shaped, similar to the flowers of Queen Anne's lace. It blooms from June to July, and produces fruit from July to August. This species is considered indigenous to either Egypt, or regions of Europe and the Middle East/West Asia. It also grows scattered across the British Isles, including in North and Central Scotland, is widely distributed across the Mediterranean region (including Southern Europe and North Africa), and can also be found in West Africa and Abyssinia. As early as 2000 BC in Egypt, the juice of Ammi majus was rubbed onto vitiligo patches, after which patients were told to sunbathe. In the 13th century, vitiligo was treated with a tincture made of honey and powdered seeds from a plant called "aatrillal", which was common in the Nile River Valley. This plant has since been identified as A. majus, and the trade name Aatrillal is still used today for the yellowish-brown powder made from its seeds. Ammi majus contains large amounts of the furanocoumarins bergapten and xanthotoxin (also called methoxsalen), two psoralen derivatives that are well known for their photosensitizing effects. A. majus is likely the world's main source of methoxsalen. The historical use of Ammi majus to treat vitiligo relies on the hyperpigmentation effects triggered when a photosensitizing agent like methoxsalen is used followed by ultraviolet radiation exposure. Too much of either the photosensitizing agent or subsequent UV exposure can cause phytophotodermatitis, a serious skin inflammation. Despite this risk, A. majus is cultivated for its furanocoumarins, which are still used to treat skin disease, particularly the furanocoumarin xanthotoxin that is also called "ammoidin" and sold under the brand name "Oxsoralen". Like its close relative Ammi visnaga, A. majus and its cultivars are commonly grown in gardens from seed annually. Both the species itself and the cultivar 'Graceland' have received the Royal Horticultural Society's Award of Garden Merit.
