Dracaena draco, the Canary Islands dragon tree or drago,[4] is a subtropical tree in the genusDracaena, native to the Canary Islands, Cape Verde, Madeira, western Morocco, and possibly introduced into the Azores.[5]
A related tree of similar appearance, the Socotra dragon tree Dracaena cinnabari, grows on the island of Socotra, Yemen, more than 7000 km from the Canary Islands.
Description
Dracaena draco is an evergreen long lived tree capable of exceeding 15 m (49 ft) in height and having a trunk of 5 m (16 ft) or more in circumference, starting with a smooth bark that evolves to a more rough texture as it ages.[8] The "dragon tree" is a Monocot, with a branching growth pattern currently placed in the asparagus family (Asparagaceae, subfamily Nolinoidae).[9] When young it has a single stem. At about 10–15 years of age the stem stops growing and produces a flower spike with white, lily-like perfumed flowers, followed by coral berries. Soon a crown of terminal buds appears and the plant starts branching. Each branch grows for about 10–15 years and re-branches, so that a mature plant has an umbrella-like habit. It grows slowly, requiring about 10 years to reach 1.2 metres (4 ft) in height, but at times, grows much faster.[clarification needed][10]
Despite being a monocotyledon, it has annual growth rings. There is considerable genetic variation within the Canary Island dragon trees. The form found on Gran Canaria is now treated as a separate species, Dracaena tamaranae, based on differences in flower structure. The form endemic to La Palma, initially branches very low with numerous, nearly vertical branches arranged fastigiately. There is a forest of such trees at Las Tricias, Garafia district, La Palma.[11][12]
Subspecies:
D. draco subsp. draco: Endemic to Madeira and Canary Islands[13]
D. draco subsp. ajgal Benabid & Cuzin: Endemic to Morocco[14]
D. draco subsp. caboverdeana Marrero Rodr. & R.S.Almeida: Endemic to the Cape Verde islands[15]
Distribution and habitat
Dracaena draco is native to Macaronesia and southwest Morocco, where it is commonly cultivated as an ornamental plant. On the Canary and Madeira archipelagos, wild endemic populations today are known only in Tenerife and Madeira after recently going extinct in the wild in Gran Canaria. Wild populations in Morocco extend to the southwest Atlas Mountains. Its origin on the Azores is uncertain but it is thought to result from an introduction made by the Portuguese prior to 1500 with seeds from Madeira and Cape Verde, as some individuals were observed to have similarities with the Cape Verdean subspecies (subsp. caboverdeana); there are around 200-300 individuals on remote sites in the island of São Jorge and a few more on other islands and it is unknown if these populations can be considered native or the result of an early introduction.[5][16]
Uses
When the bark or leaves are cut they secrete a reddish resin, one of several sources of substances known as dragon's blood. Red resins from this tree contain many mono- and dimeric flavans that contribute to the red color of the resins.[17] Dragon's blood has a number of traditional medical uses, although dragon's blood obtained from Dracaena draco was not known until the 15th century,[18] and analyses suggest that most dragon's blood used in art was obtained from species of the genus Calamus formerly placed in Daemonorops.[19] The primary and secondary plant body are the site of the secretory plant tissues that form dragon's blood. These tissues include ground parenchyma cells and cortex cells.[20] Dragon's blood from Dracaena draco and Dracaena cinnabari can be distinguished by differences in 10 compounds and a dominant flavonoid DrC11 missing in Dracaena draco.[19]
The Guanches worshiped a specimen in Tenerife, and hollowed its trunk into a small sanctuary. Humboldt saw it at the time of his visit. It was 70 feet (21 m) tall and 45 feet (14 m) in circumference, and was estimated to be 6,000 years old. It was destroyed by a storm in 1868.[21]
The Museum of Wine on Pico Island, Azores, has one of the largest concentrations of this species in Macaronesia, some being more than 100 years old.[26]
^Linnaeus, C. (1767). "Dracaena". Systema Naturae: Per Regna Tria Natura, Secundum Classes, Ordines, Genera, Species, Cum Characteribus, Differentiis, Synonymis, Locis (Ed. 12). 2: 246.
^ abBaumer, Ursula; Dietemann, Patrick (2010-06-01). "Identification and differentiation of dragon's blood in works of art using gas chromatography/mass spectrometry". Analytical and Bioanalytical Chemistry. 397 (3): 1363–1376. doi:10.1007/s00216-010-3620-0. ISSN1618-2642. PMID20349349. S2CID13267387.
^Jura-Morawiec, Joanna; Tulik, Mirela (2015-05-01). "Morpho-anatomical basis of dragon's blood secretion in Dracaena draco stem". Flora - Morphology, Distribution, Functional Ecology of Plants. 213: 1–5. Bibcode:2015FMDFE.213....1J. doi:10.1016/j.flora.2015.03.003.
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'Académie des Sciences Série III Sciences de la Vie 320(3): 267–277.