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Dendrocnide:
the Stinging Trees |
- There are 6 species within this genus, 2 of which are actually trees
(D. excelsa-the Giant Stinging Tree, and D. photinophylla,
the Shiny Leaf Stinging Tree), and 4 are shrubs (D. moroides,
the Gympie-Gympie, and D. cordifolia); all are locally referred
to as "Stingers"
- They are mostly found along Australia's eastern coast, especially
in the rainforest of the northeast (Queensland)
- Like other nettles, they tend to grow in disturbed areas, especially
forest clearings and riverbanks (Hurley, 2000) ("Moonlighter...")
- The Giant Stinging Tree can grow up to 40m (~130ft) in height, while
the shrub species only reach 1-2m (3-7ft) ("Contact Urticaria")
("Moonlighter...")
- They have broad, heart-shaped leaves as big as dinner plates, which
are quickly regrown after being damaged/eaten
- Like other nettles, they are covered with thousands of tiny stinging
hairs, even on the fruits; the larger trees, however, usually don't
have hairs on their trunks
- Many animals feed on the leaves and fruits of the stinging trees,
including spiders, scarab beetles, green ants, mites, katydids, sapsuckers,
leaf hoppers, assassin bugs, snails, frogs, lizards and birds; the
worst herbivores are the shiny green-black beetle (Prasyptera mastersi)
and the redlegged pademelon (Thylogal stigmatica) (a small
wallaby) (Hurley, 2000)
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The Sting:
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- The sting of Dendrocnide is far worse than any species of
Urtica ("Contact Urticaria"); they have been known
to kill dogs and horses that have bumped into them, and there are
stories of human fatalities, but with only one official death (Hurley,
2000) (Everist, 732)
- Marina Hurley, a leading researcher of stinging trees, found that
the only way she could handle the plant to study it was with heavy
welding gloves
- A military officer supposedly shot himself to be rid of the pain
of the sting, and another had to be restrained in his hospital bed
for three weeks (Hurley, 2000)
- On the cellular level, one study concluded that the chemicals acted
like Acetylcholine, Histamine, and Serotonin, but were actually different
chemicals ("Moonlighter...") (Everist, 730); not enough
research has been done on this topic
- The hairs are often so small that the skin closes over them, and
any contact or hot or cold temperatures on the site can be painful
for up to a year after the initial sting (Hurley, 2000)
- In addition, the toxin doesn't seem to be affected by time or by
heat; samples that have been in museums for decades can still sting
("Moonlighter...")
- The best first aid that has been found is to apply wax hair-removal
strips at room temperature and then yank them off to remove the hairs
(Hurley, 2000)
- Chopping and slashing of the plants can cause excessive sneezing
and intense throat irritation (Everist, 731); Australian forestry
workers carry gloves, respirators, and antihistamines to prevent this
("Moonlighter...")
- D. moroides is definitely the most virulent of all the species
("Moonlighter...") (Everist, 733)
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© Copyright 2001 Department of Biology,
Davidson College, Davidson, NC 28036. Send comments, questions, and suggestions
to: kabernd@davidson.edu
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