The Frankincense and Myrrh of the Desert:
Bursera and Pachycormus discolor
by Cheryl Miller
Gnarled, thick-footed, naturally tortured works of art, the Elephant Trees of Baja consist of 9 species and
sub-species hailing from actually two distinctly different plant families
All Elephant Trees, are so called, because of their stout trucks and bases reminiscent of an elephants’ leg or foot. All Elephant Trees are caudiciforms, which are considered to be succulents. A caudiciform is a characteristic of morphological development and doesn’t relate to family relation. The common attribute is merely the storage of water within the trunk or base during rainy seasons for use during drought periods. This trait makes the caudiciform a perfect desert organism and they can be found all over the world, as well as, our Baja.
And all Elephant Trees also prefer rocky soils, volcanic and rocky hillsides and dry washes.
The first family, the Torchwood or Burserceae Family has 20 genera and over 300 species worldwide, but contributes 2 of those species and 6 sub-species to our Baja desert environment. This family is known for its fragrant leaves and resins, a main feature that distinguishes this family from the other Elephant Tree family, Anacardidiaceae or Sumac or Cashew Family. To give this a little perspective, a specie of Bursera on the mainland is most famous for producing copal, a Mayan and Aztec resin gum, still used as incense today. Another specie from Somalia, Yemen and Oman is known for the biblical frankincense; and another, from the Middle East, is known for myrrh. Both frankincense and myrrh are prized, expensive oils and resins on today’s market after millennia of use as incense, embalming oils and perfume. Our Baja Torchwood species are no exception.
The 8 species of the Bursera trees in Baja all have aromatic leaves and resin too, although they have not been of any major commercial use, they have been used by the natives for ritualistic burning and aromatic medicinal purposes for centuries. Life spans of the Bursera varieties in Baja have been recorded to live as much as 800 years.
Bursera microphylla is probably the most common and widespread of the Torchwoods here in Baja. Torote or Torote Colorado (red), as they are called in Spanish, are a low branched, spreading tree that grows to as much as 8 meters high. They can be found as far north as California, Arizona and Texas, and B. microphylla is prevalent in the Sonoran and Chihuahua deserts on the mainland as well. Its aromatic leaves and branches have a turpentine-like smell and are distinctive for their reddish-brown end twigs and branches that do not thicken as does the trunk. The trunk thickens and swells as it stores water during the rainy season and has a grey, tissue-paper-like bark that exfoliates in curls exposing a yellowish new layer of bark beneath. All species of the Bursera are drought deciduous and fall dormant in the dry months displaying only its minute inconspicuous white flowers during only the hottest months of the year. The leaves of the B. microphylla are aptly name “micro” as they are evenly pinnate, and fine-like lace. The turpine sap is pleasant smelling to humans, but animals find it foul. A herbivore will leave the leaves and bark intact without eating them. The sap is also under pressure so that when you bend and break a leaf, a squirt of sap spurts out nearly an inch; and that “squirt-in-the-eye” defence apparently is very effective with animals. Baja Indians used the bitter fruit to quench thirst, as it stimulates saliva, they used the sap to repair boats and cracks in pottery, and medicinally, to treat stingray wounds, lice, cuts and gonorrhoea. The bark was used in tanning leathers and a tea was brewed from the twigs for stomach aches.
B. microphylla has 2 sub-species B fillcifolia and B. fagarioides which differ slightly in stature, leaf (a bit heavier than microphylla) and fruit, slightly different. Some of these sub-species get no larger than a large bush and are quite squat, while others grow to 12 feet high. A new species, not yet named, has recently been found near La Paz. How about that? Recent botanical history being made in our neighbourhood!
The second major specie of Bursera in Baja is Bursera hindsiana. A much shorter tree at up to 3 meters high, with grey papery trunk and branches and red twigs, it major difference is in its leaf structure. Unlike the lacy microphylla leaves, hindsiana simple leaves are oval to obtuse, similar to the jatropha but, with scalloped edges and fuzzy. B. hindsiana has larger flowers than the B. microphylla, which bloom between September and December. Also called Copal, Torote and Torote Prieto the aromatic gum has an interesting and pleasant smell. The fruit are an ovoid red to yellow drupe that is a favorite source of food for birds.
The 4 sub-species of the B.hindsiana include B. cerasifolia, B. epinnata, B. odorata and B. laxiflora. The differences are so slight that unless they are flowering or have leaves, it is very hard to distinguish. Other names for the sub- species include Torote Blanco (B. odorata) for its whiter coloured papery bark, and simply “Copal” for B. epinnata.
Modern uses of our Bursera family Elephant Trees include xeri-scape landscaping, where in certain relatively dry states such as Arizona, the tree does very well with little water. Too much water can result in dry rot of the roots, as the tree actually goes fully dormant several months of the year.
So, the above 8 species belong to the Burserceae Family, leaving the last specie, the Pachycormus discolor as the last Elephant Tree in Baja. As previously stated, this specie belongs to a completely different family, the Anacardidiaceae or Sumac Family and it is the ONLY one of this family in all of Baja that is considered an elephant tree or caudiciform. In fact, this succulent holds up to 58% more water than the Bursera Elephant varieties. In addition, this tree grows no where else on earth, except our beautiful Baja.
“Pachy” refers to Pachyderm or elephant; and “cormus” means foot in Latin.
Unlike the Bursera varieties, the Torote Blanco or Copalquin, does not go into full dormancy, nor is it fully deciduous. It white paper like bark, also curls like tissue paper, but it reveal a green underlying bark that has some photosynthetic capabilities that augment the trees ability to survive when the tree drops the majority of its leaves. The flowers, which appear between May and September, are also small and a cream to pink in color, and a re a favorite for hummingbirds. The tree can grow as tall as 20 feet high. The Torote Blanco is abundant in the central deserts and in the Sierra Gigante, but no where can seen a better display of this species than in the volcanic rocky slopes near the Tres Virgines volcano region, just north and east of Santa Rosalia on Highway 1, where almost pure stands of this tree exist.
The Pachycormus discolor is a really long lived plant. Estimated life spans are upwards of 2,000 years. When historical photos are compared to modern photographs, the Boojums and Cardons in the area have completely lived out their life cycles. Imagine when you pass a tall Copalquin that it may have been there establishing its new life when Jesus walked the earth!
“Pachy” is so hardy is this species that it is rare to find one dead or dying.
On windswept volcanic hillsides this tree has even been known to “lay down” along the steep hillsides and grow vertically up the slope. But the slow growth and long life of this tree has created a demand among bonsai enthusiasts and is often found potted as a rare specimen.
THE ELEPHANT TREES are an example of a classic example of convergent evolution – these two genetic specie groups, the Pachycormus discolor and the Bursera varieties here in Baja have evolved with the same adaptations to cope with particular environmental circumstances, including fairly easy reproduction through seeds. However, there is a major ecological difference between these two plants - only Pachycormus responds to winter rainfall by growing and producing leaves. Burseras are dormant in winter. Enjoy our elephants of the desert!