Perhaps the most prominent and
distinct plant that evocatively named “Dragon’s Blood Tree” has a unique and
bizarre appearance, it is overturned, densely-packed crown having the shape of
an upside-down umbrella. Dragon’s blood trees are a unique and slow growing but
potentially long-lived species that is very native to the Socotra archipelago
off the horn of Africa. It is so popular due to the red sap that the trees
produce. The prominent red resin that gives it its name is exuded from the bark
after wounding. This evergreen plant is a substance which has been highly
prized since ancient times, and has been the major commercial source of this
resin, and many myths surround the rare trees. The “dragon’s blood” resin of
this tree exudes naturally from fissures and wounds in the bark, and is
frequently harvested by widening these fissures with a knife. The resin has had
numerous different uses since ancient times, including to color wool, varnishes
and plaster, to decorate houses and pottery, and in ritual magic. It is also
used for many medicinal purposes, including as an antiseptic, antiviral,
anti-diarrhetic, and for treating tumors, and in addition contains compounds
with beneficial antioxidant properties.
The medicinal and coloring
properties of this resin, and that from other dragon trees, was recorded by the
ancient civilizations of Greece and Rome. It continues to be used in medicine,
dyes, varnish and incense to this day. Similar to other monocotyledons, such as
palms, the tree grows from the tip of the stem, with the long, stiff leaves
borne in dense rosettes at the end. However, contrasting too many palms, the
dragon’s blood tree branches at maturity to produce the characteristic
umbrella-shaped crown with the leaves, which measure up to 60 centimeters long
and 3 centimeters wide, remaining crowded at the branch tips. Dragon’s Blood
Trees trunk and branches are thick and stout, and show ‘dichotomous’ branching,
in which each branch repeatedly divides into two. The first description was
made in 1835 when The East India Company led by Lieutenant Wellsted made a
survey of Socotra and gives the description to Pterocarpus Draco, but in 1880,
the Scottish botanist Isaac Bayley Balfour made a formal description of the
species and renamed it as “Dracaena Cinnabari”. Of between 60 and 100 Dracaena
species, D. Cinnabari is one of only 6 species which grows as a tree.
The tree usually flowers in Feb;
however exact flowering time may vary and depends on location. Normally flowers
grow at the ends of the branches, comprises of branched inflorescences bearing
clusters of small, fragrant, white or greenish flowers. The fruit usually takes
five months to completely develop, which is small fleshy berry that transform
from green to black as it ripens, to end becoming orange-red, and containing
between one and three seeds. The berries may be eaten by animals and birds,
including domestic livestock, which then act as seed dispersers.
Due to its
unique flora and fauna, the Socotra Archipelago is designated as a World
Heritage Site, a WWF Global 200 Ecoregion, a Centre of Plant Diversity and an
Endemic Bird Area, and it also lies within the Horn of Africa biodiversity
“hotspot”. Numerous initiatives are underway to aid sustainable development and
biodiversity management on Socotra & the dragon’s blood tree is considered
an important flagship species for conservation on the island, and an “umbrella
species”, whose protection would also benefit many other plants and animals.
Dragon’s
Blood Tree is usually found at elevations of 300 to 1,500 metres, preferring
limestone-based soil and naturally growing in evergreen or semi-deciduous
woodland. It is the only tree-forming Dracaena species to form dense woodland
and frequently appears to grow well in areas of solid rock pavement with
wide-ranging cracks, down which water and soil can flow after rains, however;
as long as moisture and nourishment for the roots. The tree’s pattern of
distribution closely matches the areas of the island that experience normal low
cloud, rain and drizzle during the monsoon season.
The Drangon’s Blood Tree bizarre
shape assists to survive in often arid conditions and on mountaintops with
little soil. Early morning mists condense on the waxy, skyward-pointing leaves,
the water then channeling down the trunk to the roots. The vast densely packed
crown also offers highly effective shade, so dropping the evaporation of any
water drops that fall to the ground, and giving shade to the tree’s roots. This
shading allows seedlings to survive better beneath the adult tree than in full
sun, which could be why many dragon’s blood trees grow close together.
The
dragon’s blood tree is still relatively widespread, but its range has become
abridged and fragmented, and various populations are suffering from poor
regeneration. Though human activities may have play a bigger contribution to
this deterioration, like overgrazing and the feeding of the flowers and fruit
to livestock, the main threat to the species is thought to come from the
gradual drying out of the Socotra Archipelago, a process that has been ongoing
for the last few hundred years, but which may be exacerbated by global climate
change. In many cases, the trees are failing to flourish, and the extent and
duration of the mist and cloud brought by the monsoon appears to be decreasing.
Growing aridity is foreseen to cause a 45 % dropping in available habitat for
this species by the year 2080.
Other
impending threats to the dragon’s blood tree, such as harvesting of its resin
and the use of its leaves to develop rope, have decreased in recent years and
are currently small-scale, but in future rise in demand could potentially lead
to over-collection. Some dragon’s blood trees have been felled to make
beehives. Though this was usually condemned, and it illustrates how the species
may be threatened by a breakdown in traditional practices on the island.
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