Dragon Tree

I am reading Humbolt’s Cosmos by Gerard Helferich and came across an interesting item. There exists on Tenerife a very old dragon tree that was then fifty feet around and the author states that it is still in place.

The text suggests that the species is the same as that in Central America and suggests a puzzle at least. It certainly suggests a research program in which these trees are identified as to genetic signature. The tree in question is surely pre Columbian and that offers an opportunity to determine possibility of human transmission for these plants. That it may be African was not contemplated when this book was written but it now needs to be investigated.

The plant is very old and obviously difficult to age. It also was surely planted by human agency. It is plausible that the tree in central America was also transplanted there by human agency. The age of the tree can be judged by a raw count of the flowering nodes and perhaps carbon fourteen dating.

The age of these trees and the great likelihood of human transportation makes it an excellent research tool. There are no growth rings to make it simple, but each unique node will have a unique age signature. That means the sampling will be costly, but methods today use little of the material so sampling will not harm the tree.

Plenty of comparable trees exist in Morocco and somewhere in Central America, so an extensive sampling program will gives us a long data base. We do not even know just how old the oldest are, but the slow growth suggests something that competes with the bristle cone pine. We may be totally wrong on this, but it needs to be explored.

Dracaena draco

From Wikipedia, the free encyclopedia

Dracaena draco, the Canary Islands Dragon Tree or Drago is a subtropical Dragon Tree native to the Canary Islands, Cape Verde, Madeira, Azores, and locally in western Morocco.

The tree is characterised by a single or multiple trunk growing up to 12 m tall (rarely more), with a dense umbrella-shaped canopy of thick leaves. It grows slowly, requiring about ten years to reach 1 m tall. Young trees remain with only a single stem; branching occurs when the tree flowers, when two side shoots at the base of the flower panicle continue the growth as a fork in the stem. Being monocotyledonous, Dracaena draco does not display annual rings and age can only be estimated by the number of branch forking occurrences (indicating the number of flowering episodes) and measuring the frequency of flowering (less than annual). Some specimens are believed to be up to 650 years old; the oldest is growing at Icod de los Vinos in northwest Tenerife.

The recently discovered wild populations in western Morocco have been described as a separate subspecies, Dracaena draco subsp. ajgal, while those on Gran Canaria are sometimes distinguished as a separate species Dracaena tamaranae.

When the bark or leaves are cut it secretes a reddish resin, one of the sources of the substance known as Dragon's blood.

References

Bibliography

Bañares, A. et al. (1998). Dracaena draco. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Listed as Vulnerable (VU A1abcde v2.3)
Arkive: Dracaena draco factsheet.
Dracaena draco in Morocco (photo gallery).

The climate requirements for Dracaena draco defined by its borders: Northernmost tree in the world, near 40°, northern Azores Islands and Southernmost dragon tree in the world, near 38°, Victoria, Australia (photos).

Benabid, A. & Cuzin, F. (1997). Dragon tree (Dracaena draco subsp. ajgal Benabid et Cuzin) populations in Morocco: Taxonomical, biogeographical and phytosociological values. Comptes Rendus de l'Academie des Sciences Serie III Sciences de la Vie 320(3)