ammoniacum

Ammoniacum or gum ammoniac is a gum-resin exuded from the several perennial herbs in the genus Ferula of the umbel family (Apiaceae). There are three types of ammoniacum: the gums ammoniac of Cyrenaica, of Persia (the commercial one today), and of Morocco.

== Ammoniac of Cyrenaica == Ammoniacum was first documented in the 1st century by Dioscorides in his De materia medica. It got its name from the Temple of Jupiter Ammon in ancient Libya (located in the Siwa Oasis of Egypt today) near which it was produced. It is called the gum ammoniac of Cyrenaica to differentiate it from the commercial one used today, and its source plant has been identified as Ferula marmarica native to Libya and Egypt. The export of the gum ammoniac of Cyrenaica to Europe declined after Arab and Turk domination of the Middle East, but probably continued at least until the 18th century, as Linnaeus still cited Libya and Egypt as the places of origin of ammoniacum in his Materia medica.