During this dark time of year we sometimes sing songs with words that make little sense to us these days.

“We three kings of Orient are bearing gifts from travels afar…”

Those kings had three precious items: gold (a mineral) and frankincense and myrrh (tree resin). Why did they have it? What is it? What does it look like? What is it used for?

I used to think they were just foreign words describing spices, but I didn’t know why they should be so valuable as to compare with gold. Odor is an important quality of frankincense and myrrh as it is for spices, and, like cinnamon, it comes from trees. Cinnamon is ground from the bark of a particular tree of the same region, but frankincense and myrrh are tree (or sometimes shrub) pitch.

I teach a landscape plant class and was studying up on balsam fir (Abies balsamea). It grows in northeast North America and its resin is sometimes collected. That resin is called balsam. Trying to pin down just what this meant led me from one source to another. It turns out that pitch, tree resin, varies in its qualities, but has been used by humans throughout history for waterproofing, medicine, incense, cosmetics, paint, thinner, varnish, and a good deal more. And, what it has in it determines its use and its name.

Balsams consist of resins dispersed in benzoic or cinnamic acid esters and are used chiefly in medicinal preparations and sometimes in incense. Ironically, the resin from balsam fir is an oleoresin, dissolved in essential oil, and not a true balsam.

Frankincense and myrrh are gum resins. Frankincense, also known as olibanum, comes from select trees in the genus Boswellia, and myrrh usually comes from Commiphora trees. The plants belong to the same botanical family, Burseraceae. Several sources reported that the highest quality of these particular gum resins come from the Arabian Peninsula, while lesser quality comes from Somalia in northeastern Africa, and the least quality from India.

It’s harvested by making incisions in the barren, thorny trees. They ooze resin, and once exposed to air and sun, the resin dries. Myrrh hardens to reddish-brown pea-sized chunks, whereas frankincense dries to pale yellow, tear-shaped droplets about half that size.

The chemistry of these two resins quickly becomes complicated, so I’ll leave that aspect alone. Their useful qualities are many: pain relief, antiseptic, anti-depressive, anti-anxiety, embalming (myrrh), incense. The two together were a pharmacopeia in a box.

The whole tree resin situation fascinated me so much that I ordered a book about it. In the meantime, here are two interesting sites, but there are many others:

http://pubs.acs.org/cen/whatstuff/86/8651sci2.html

http://www.britannica.com/EBchecked/topic/50870/balsam