By Christina Stapley B.Sc. Hons Phyt. MCPP
The aim of this blog is to highlight the valuable possibilities for enlivening and enriching the reading, and interpretation of herbals and herbal histories through investigating archaeological sources. In this case – four UNESCO World Heritage sites and museums in Oman. These are Wadi Dawkah Natural Reserve, Samhuram Archaeological Park, AL Baleed Archaeological Park, which includes Museum of the Land of Frankincense and Wubar Archaeological Park. On my recent visit to Oman, I was also able to see many trees of frankincense, Boswellia sacra Flueck at Wadi Dawkah (Khan et al, 2017).
Ancient Incense Trade Route
Supported by geology and archaeological evidence of trade in shells and obsidian it is concluded that pastoral nomads in Dhofar, Oman had already established the ancient trade routes to southern Mesopotamia in the Neolithic period. Early importation of frankincense is also supported. This suggests an inland route existed across the Rub al Khali [gravel desert towards the Saudi Arabian border] and ultimately to Mesopotamia, possibly as early as the sixth millennium BC (Zaris, 2001, pp. 53,55).
Written in the 1st century AD the Periplus (Schoff, 1912) gives the main source of frankincense supply as Arabia Felix; in particular the Hadramaut and province of Dzofar. In addition to shipments from the port of Moscha to India, Persia and Egypt, resin was carried overland by camel trains from Dzofar to Petra and on to Gaza and Syria. According to Pliny, the journey from the collection point, the city of Sabota, where a tithe was paid on the volume of incense, to Gaza was split into 65 camel-halt stages.
The route to Gaza was pointed out by Professor Sprenger in the nineteenth century. (Flückiger and Hanbury, 1879). Classical writers mentioned a city early on this route, called “Ubar.” In 1930 Bertram Thomas, the first westerner to cross the Empty Quarter searched for this “Atlantis of the Sands”. Evidence of the ancient road from EOSAT/LANDSAT and SPOT enhanced images in 1991 led to substantial archaeological finds including a hilltop fortress, close to Shisr. There is now a UNESCO heritage site with a small museum marking “Ubar.”
Ports and Sea Trade
The Periplus mentions the port of Moscha Limen beyond Omana, from which frankincense was exported. Indian merchant vessels were recorded there. The only Iron Age B (325-650 AD) site on that coast, the inlet, Khor Rori with adjacent Samhuram have been identified as Moscha Limen. The identification is further supported by finds of coins, ceramics and a bronze figurine of Salabhanjika, an Indian tree goddess (Zarins, 2001).
AL Baleed, the third UNESCO coastal site (formerly al Mansura), was described by Marco Polo as trading in frankincense. Remains of an underlying Iron Age city may reveal more of earlier frankincense trade.
Confusion in the Past.
The exact nature of the frankincense tree remained a mystery for centuries. Hill (1751) wrote, “If we are uncertain as to the Place whence the Olibanum is brought, we are much more so as to the Tree which produces it.” By 1879 Flückiger and Hanbury gave scant detail of Boswellia spp. in India and Somalia, with only a reference to Carter (writing in 1844-46) for B. sacra in Arabia at Ras Fartak and near Merbat, Oman. Langenheim (2003) quotes differing opinions in the late twentieth century on how many species of Boswellia produce frankincense in this area. If the taxonomy remains complex we can now see the tree in cultivation for ourselves.
Frankincense Cultivation in Oman today
I was excited to see frankincense in flower at the fourth UNESCO site in Wadi Dawkah a stony semi-desert area 40km north of Salalah. Frankincense grows here naturally and there is a plan to increase the total number of trees to 10,000. Younger trees in a fenced nursery are irrigated as necessary. Boswellia sacra has a haphazard growth, up to 5m tall. The racemes of delicate cream flowers have a faint honeyed scent. These are followed by green oval fruits which turn brown. While pinnate leaves offer little surface for evaporation of water, papery strips hang away from the bark.
The trees are harvested from the age of 8-10 years, being rested after several harvests. The gum resin exudate hardens into pale, sweet, soft lumps. A special knife known as a manqaf is used to make an initial surface wound in the bark. The first resin to ooze from the wound is not commercially viable. Three weeks later this is removed and a second slightly deeper wound yields more to be collected when the third wound is made after three weeks. The sum of collections may give 3-4 kg of frankincense each year.
The antibacterial and anti-inflammatory uses of the resin have been commented on since ancient times, with Dioscorides’ recommendations for treating wounds and ulcers quoted by Gerard (Johnson, 1975). Hill (1751) wrote “It is esteemed by many as a Specifick in Pleurisies, especially when epidemic. Externally it is used in Fumigations for Disorders of the Head and against Catarrhs and is an Ingredient in some Plaisters.”
By the following century frankincense falls almost into disuse in western medicine apart from use in inhalations. However, today species used as herbal medicines include B. papyfera and B. sacra from northeastern Africa and Oman; B. frereana and B. serrrata from India. Current focus of research is on the anti-inflammatory action of boswellic acids in B. serrata which has a long history of use in Ayurvedic medicine. The inhibition of a single enzyme in the inflammatory cascade makes Boswellia suitable to treat arthritic and rheumatic conditions, ulcerative colitis and asthma (Science Direct, 2018). Indeed, I can verify use of frankincense in herbal medicine, both as a practitioner and a patient, having taken it for 17 years as, in my case, a very effective anti-inflammatory for a chronic rheumatic condition.
Flückiger, F., and Hanbury, D., (1879). Pharmacographia. A history of the principal drugs of vegetable origin (2nd ed). London: Macmillan & Co. [online] Available at: https://archive.org/details/b21355022/page/n5 [Accessed 19 Nov 2018].
Hill J., (1751). A history of the materia medica. London: Longman, Hitch & Hawes. [online] Available at: https://books.google.co.uk/books [Accessed 19 Nov 2018].
Johnson T. (ed.)., 1975. The Herbal. New York, NY: Dover Publications.
Khan, A. et al., (2017). The First Chloroplast Genome Sequence of Boswellia sacra, a Resin-Producing Plant in Oman. PLoS One, 12(1), e0169794. doi: 10.1371/journal.pone.0169794 [online] Available at: https://www.ncbi.nlm.nih.gov/pubmed/28085925
Langenheim, J.H., (2003). Plant resins: chemistry, evolution, ecology, ethnobotany. Portland, OR: Timber Press.
Schoff, W., (Translator) (1912). The Periplus of the Erythræan sea; travel and trade in the Indian Ocean. New York: Longmans, Green, see pp. 31-35, notes pp. 39, 40, 50. [online] Available at https://archive.org/details/cu31924030139236/page/n5 [Accessed 19 Nov 2018].
Science Direct (2018). Boswellia – an overview. [online] Available at www.sciencedirect.com/topics/agricultural-and-biological-sciences/boswellia [Accessed 4 Dec 2018].
Zarins, J., (2001). The land of Frankincense. Muscat, Oman: Sultan Qaboos University Publications.