The plant products that accompanied the first Christmas Day, according to traditional Christian belief, are described in in Matthew 2:9-11, which relates the story of the Three Wise Men.
... and, lo, the star, which they saw in the east, went before them, till it came and stood over where the young child was. When they saw the star, they rejoiced with exceeding great joy. And when they were come into the house, they saw the young child with Mary his mother, and fell down, and and worshipped him: and when they had opened their treasures, they presented unto him gifts; gold, and frankincense, and myrrh. [King James Version]
After encountering this passage, over the centuries perhaps millions of the perplexed have asked: What the hell are frankincense and myrrh? This is a question for the Fruit Explorer since frankincense and myrrh are both aromatic resins (this term is explained below) derived from trees in the family Burseraceae, variously called the torchwood family (since the resins burn well), the incense tree family, or the frankincense and myrrh family.
Frankincense
The Frankincense Plant
Frankincense comes from a number of trees in the genus Boswellia, but most of it comes from B. sacra, which is a small (up to 25 feet), scraggly tree that is so hardy that it can grow out of solid rock. The requirements of this tree are:
The trees require an arid climate where moisture is provided by morning mist. The few ideal environments in the world for this small prized tree are found in Southern Arabia (Oman and Yemen), India, and Northern Africa (Somalia, Ethiopia, Eritrea and Kenya). Further, frankincense trees require a limestone-rich soil and are mostly found growing on rocky hillsides and cliffs, or in the dried riverbeds below.
Below are pictures of the frankincense tree. Note the blasted environments where these trees grow, except for the last one, which is growing in Biosphere 2.
Below are pictures of the leaves and flowers.
Below is a range map for Boswellia sacra. As you see, this species of frankincense grows in patchy areas in southern Arabia and the Horn of Africa.
Production and Use of Frankincense
Resins are a thick, sticky exudate that oozes from a plant and protects it against herbivores and pathogens. While saps are often sticky, they should not be confused with resins since saps, unlike resins, transport nutrients. We have seen many cases in which plants produce substances to protect themselves from herbivores, e.g., chocolate (16 May 2015) and spices (9 Oct 2015), so resins are just another weapon in the defensive arsenal of plants. An unusual example is amber, which is a fossilized resin from prehistoric trees. Another example is pine resin, which gives rise to both turpentine and rosin, which is familiar to baseball fans. If you have ever hiked a steep trail, grabbed a pine sapling so you could pull yourself up, and gotten a sticky substance on your hand that you spent the rest of the day trying unsuccessfully to get off, then you have had an unpleasant encounter with a resin. The presence of resins explain why pine burns so well in a campfire. Also, retsina, a Greek wine, is flavored with resin from the Aleppo pine. Here are some pictures of resins.
- Pine resin.
- Resin from an Araucaria columnans. Recall that the monkey puzzle tree is in the genus Araucaria. (I can't put my hand on the e-mail that deals with the monkey puzzle tree.)
- Cretaceous wasp trapped in amber. Recall that is Jurassic Park dinosaurs were reconstructed from DNA found in insects that had fed on dinosaurs and then been trapped in amber.
The process of harvesting frankincense resin is described by this site.
Harvesting the resin requires a specially designed knife. A week before the harvest begins, strategic slashes are made in the outer bark which allow the liquid resin to ooze out. Another harvesting method used is to simply scrape away portions of the bark without making deep incisions and allowing the resin to flow from this wound. When the resin hits the oxygen, it starts to crystallize and harden.
These hardened resins are called tears. The longer it is left on the tree, the harder it gets. It takes about a week for the resin to harden up enough to be cut it off as a hardened resin crystal.
Here is another description of the harvesting process with more details by the UN's Food and Agricultural Organization (FAO):
Most resin is obtained by making deliberate incisions into the bark of the tree. The milky liquid that exudes hardens on exposure to air into droplets or "tears" which are then easily detached by the collector. Occasionally, some tears are produced by accidental injury or from splits which occur in the stems or branches of the tree.
Details of the tapping, particularly the time of year it is undertaken, its duration and the interval between individual tappings, vary according to the species and the customs in the area of production. In Somalia, there are usually two periods when B. sacra (B. carteri) is tapped, each lasting 3-4 months and involving successive tappings at approximately 15-day intervals. B. frereana is tapped over a single 8-9 month period with a longer, but variable, tapping interval. In both cases the timing of the tapping periods depends on the onset and extent of the rains.
Tapping involves removing small areas of bark from the tree, sometimes using a specially designed tool, otherwise an ordinary axe. New tapping points are made at the same place as old ones after removing hardened resin from the previous cut. If the tapping interval is short then a light scratching of the wood is usually sufficient to cause the resin to flow again.
In short, you slash a tree, come back in a week or two, and gather your frankincense, which is in hardened lumps called tears. Not a bad racket. A rough estimate is that a tree will produce 2-6 pounds of frankincense per year, but this can vary greatly depending on whether there is a drought, how often the tree is tapped, and other factors. Here are some pictures of making an incision, oozing resin, and dried lumps of resin.
Point of comparison: Pine resin is harvested differently. The resin does not form tears, so a cup-and-gutter system, similar to that used to tap rubber or maple syrup, must be used.
The crystals of hardened resin can be sold as incense, which is burned to perfume a room (see pictures below). Alternatively, to process the harvested frankincense resin into the essential oil, "...the crystal resin goes into the distillery where it is crushed into powder, put into an oil bath, and steam distilled to extract the oil from the crystal resin."
Frankincense is used in aromatherapy, cosmetics, massage, healing, and religious rituals. The Roman Catholic Church purchases most of its frankincense from Somalia, which produces a high-grade product. Frankincense is also used in perfumery and skincare. You won't be surprised to hear that cranks claim all sorts of healing properties for frankincense. If you want to follow up on this, you can check Wikipedia's treatment, or you can examime WebMD's treatment of frankincense. Frankincense is edible.
[Continued in Part 2]
