There are four types of genus Boswellia including Boswellia serrata from India; Boswellia scara from Saudi Arabia; Boswellia frereana from Somaila and Boswellia carterii frim eastern regions in Africa. The tree is small growing to a height of 3 – 7m and is related to the tree that produces myrrh. 
Boswellia carterii (Frankincense) is a base note which has a fresh, woody and spicy aroma with a hint of citrus fruitiness about it. The initial smell received is of medium strength and most people describe as pleasant to the senses it is often described as a church aroma, the oil itself is a light yellow colour with a fairly thin consistency compared to that of another base note oil like sandalwood.
Boswellia carterii is a small tree that grows wild throughout north east Africa and is native to the red sea region; it has pinnate leaves with pale pink or white flowers and yields a natural gum resin. The essential oil is obtained by deep incisions made into the trunk of the tree, from which white resinous matter exudes un large tear shapes. The oil is steam distilled from the gum resin and is produced mainly in south Arabia, Ethiopia and Somalia.
Frankincense was greatly used in a variety of ways by the ancient Egyptians and other civilisations for its properties including a beauty aid for the women for protecting and rejuvenating their skin, farmers fumigating wheat silos with it to keep moths away and the most popular the burning of the oil in temples. It also had uses for embalming, as kohl eyeliner developed from the charred resin of frankincense and as a remedy for illnesses that increase the body’s temperature. It was considered to a more precious commodity than Gold in the time of Christ due to its popularity.
Today in parts of Africa and Arabia the oil is still used for daily hygiene and a woman’s morning ritual incorporates standing over a vessel of steaming frankincense for its cleansing and pleasant scent. In the modern western world frankincense is used in massage for help with increasing circulation; help with pain regarding rheumatism, has a pronounced effect on mucous membranes and also for its remarkable effects on people who experience great grief or depression or with obsess ional states. Frankincense essential oil is anti-catarrhal, anti – depressive, anti – inflammatory, healing to the skin, anti infectious and an immuno-stimulant which makes it a good all round oil.
Spiritually Boswellia carterii is used more than many other oils for religious ceremonies, mediation and reflection. It is suggested that the scent is a strong stimulus for the human spirit that wants to be open to the heavens and communication with energies on a higher plane. It is also suggested to cleanse and clear awkward atmosphere, innermost spaces and is useful for this reason in prayer.
Frankincense consists chemically of approximately forty percent monoterpenes along with some ketones, camphene, dipentene, pinene, sesquiterpenes (cadiene), alcohols and esters. The oil is considered non toxic, non irritant and non sensitizing and as a result is one of the most extensively used aromatics worldwide today.
 Daniele Ryman, Aromatherapy Bible, Piatkus London, 2002 p101
 Daniele Ryman, Aromatherapy Bible, Piatkus London, 2002 p102
 Julia Lawless, The Encyclopaedia of Essential Oils, Harper Collins, 1992 p98
 Wanda Seller, The Directory of Essential Oil, Essex, p72