''Dendrocnide moroides'', commonly known in Australia as the stinging tree, stinging bush, Queensland Stinger or gympie-gympie, is a plant in the nettle family
Urticaceae
The Urticaceae are a family, the nettle family, of flowering plants. The family name comes from the genus ''Urtica''. The Urticaceae include a number of well-known and useful plants, including nettles in the genus ''Urtica'', ramie (''Boehmeri ...
found in
rainforest
Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...
areas of
Malaysia
Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...
and
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
.
It is notorious for its extremely painful and long-lasting sting. The common name gympie-gympie comes from the language of the
Indigenous
Indigenous may refer to:
*Indigenous peoples
*Indigenous (ecology), presence in a region as the result of only natural processes, with no human intervention
*Indigenous (band), an American blues-rock band
*Indigenous (horse), a Hong Kong racehorse ...
Gubbi Gubbi people
The Gubbi Gubbi people also known as Kabi Kabi are an Aboriginal Australian people native to south-eastern Queensland. They are now classified as one of several Murri language groups in Queensland.
Naming
As is often the case, ethnonyms dist ...
of south-eastern Queensland.
Description
''D. moroides'' is a straggly
perennial
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...
understory
In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but abov ...
shrub
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
, usually flowering and fruiting when less than tall, but it may reach up to in height. It is superficially similar to ''
Dendrocnide cordifolia'', with the most obvious difference being the point of attachment of the
petiole to the leaf blade—where ''D. moroides'' is
peltate
The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...
, i.e. the stalk attaches to the underside of the leaf and not at the edge, ''D. cordifolia'' is
cordate
Cordate is an adjective meaning 'heart-shaped' and is most typically used for:
* Cordate (leaf shape), in plants
* Cordate axe, a prehistoric stone tool
See also
* Chordate
A chordate () is an animal of the phylum Chordata (). All chordat ...
. The stem, branches, petioles, leaves, and fruits are all covered in stinging hairs.
It has large, heart-shaped,
simple
Simple or SIMPLE may refer to:
*Simplicity, the state or quality of being simple
Arts and entertainment
* ''Simple'' (album), by Andy Yorke, 2008, and its title track
* "Simple" (Florida Georgia Line song), 2018
* "Simple", a song by Johnn ...
leaves about long and wide with toothed margins, a pointed tip and a cordate to
obtuse base shape. There are six to eight pairs of lateral veins either side of the
midrib
This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...
. The petiole is quite long, about as long as the leaf blade itself, with
stipule
In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...
s around long.
![AULakeEuchamDendrocnide moroides](https://upload.wikimedia.org/wikipedia/commons/b/b1/AULakeEuchamDendrocnide_moroides.jpg)
The
inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
is
monoecious
Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy.
Monoecy is conne ...
(rarely dioecious), and is borne in the leaf
axils
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...
. It is up to long, often paired. It carries both male and female flowers which are quite small, the
perianth
The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals) or tepals when ...
measuring less than across. Flowering occurs throughout the year, but mostly in summer.
Fruits of this species are an
achene
An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...
(a tiny seed-like fruit), produced in number in a globular structure which is pink to light-purple in colour and has an appearance similar to a
mulberry
''Morus'', a genus of flowering plants in the family Moraceae, consists of diverse species of deciduous trees commonly known as mulberries, growing wild and under cultivation in many temperate world regions. Generally, the genus has 64 identif ...
. Each achene, measuring just long, is contained in a small fleshy sac which derives from the swollen
pedicel
Pedicle or pedicel may refer to:
Human anatomy
*Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures
...
. As with the rest of this plant, the
infructescence Infructescence (fruiting head) is defined as the ensemble of fruits derived from the ovaries of an inflorescence. It usually retains the size and structure of the inflorescence.
In some cases, infructescences are similar in appearance to simple fru ...
s are also covered in stinging hairs, but are edible if the hairs are removed.
Taxonomy
The
type specimen
In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...
for this species was collected in 1819 by
Allan Cunningham near the
Endeavour River
The Endeavour River ( Guugu Yimithirr: ''Wabalumbaal''), inclusive of the Endeavour River Right Branch, the Endeavour River South Branch, and the Endeavour River North Branch, is a river system located on Cape York Peninsula in Far North Queen ...
, and was first described in 1857 by
Hugh Algernon Weddell
Hugh Algernon Weddell (22 June 1819 – 22 July 1877) was a physician and botanist, specialising in South American flora.
Weddell was born at Birches House, Painswick near Gloucester, England but was raised in France and educated at the ...
as ''Laportea moroides'' in his work ''Monographie de la Famille des Urticées'', published in the journal ''Archives du Muséum d'Histoire Naturelle''. The current binomial combination was published by
Wee-Lek Chew in ''The Gardens' Bulletin Singapore'' in 1966.
Etymology
The genus name ''Dendrocnide'' has been constructed on the
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
''δένδρον'' (déndron), meaning "tree", and ''κνίδος'' (knídos), meaning "stinging needle". The
species epithet ''moroides'' is created from the genus name for mulberries ''
Morus'', combined with the
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
suffix ''-oides'', meaning "resembling", referring to the mulberry-like infructescence. The binomial name may be translated as "mulberry-like stinging tree".
Distribution and habitat
![Dendrocnide moroides small plant SF21168](https://upload.wikimedia.org/wikipedia/commons/a/ac/Dendrocnide_moroides_small_plant_SF21168.jpg)
The species occurs in and near rainforest, from
Cape York Peninsula
Cape York Peninsula is a large peninsula located in Far North Queensland, Australia. It is the largest unspoiled wilderness in northern Australia.Mittermeier, R.E. et al. (2002). Wilderness: Earth’s last wild places. Mexico City: Agrupación ...
south to northern
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
in Australia and also occurs in the
Moluccas
The Maluku Islands (; Indonesian: ''Kepulauan Maluku'') or the Moluccas () are an archipelago in the east of Indonesia. Tectonically they are located on the Halmahera Plate within the Molucca Sea Collision Zone. Geographically they are located eas ...
and
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
. It is an early coloniser in rainforest gaps, such as alongside water courses and roads, around tree falls, and in man-made clearings. The seeds germinate in full sunlight after soil disturbance. Although common in
Queensland
)
, nickname = Sunshine State
, image_map = Queensland in Australia.svg
, map_caption = Location of Queensland in Australia
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, established_ ...
, it is rare in the southernmost part of its range and is listed as an
endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...
in
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
.
Ecology
''Dendrocnide moroides'' serves as the
host plant
In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' ( symbiont). The guest is typically provided with nourishment and shelter. Examples include ...
for
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
e of the
white nymph butterfly. A variety of insects feed on the leaves, among them the nocturnal beetle ''
Prasyptera mastersi'' and the moth ''
Prorodes mimica'', as well as the herbivorous
Red-legged pademelon
The red-legged pademelon (''Thylogale stigmatica'') is a species of small macropod found on the northeastern coast of Australia and in New Guinea. In Australia it has a scattered distribution from the tip of Cape York Peninsula in Queensland to ...
, which is unique among mammals in being apparently immune to the plant's neurotoxins. Fruits are eaten by various birds that distribute the seeds in their droppings.
Toxicity
''D. moroides'' is notorious for its extremely painful sting which may leave victims suffering for weeks or even months. Researchers at the University of Queensland recently discovered that the plant produces a neurotoxin similar to that of a spider or
cone snail
A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex.
A cone is formed by a set of line segments, half-lines, or lines con ...
.
It is reputed to be the most poisonous plant in Australia, if not the world. After contact with the plant the victim will feel an immediate severe burning and stinging at the site of contact, which then intensifies further over the next 20 to 30 minutes and will last from hours to several days before subsiding. During this time the victim may get little sleep because of the intensity of the pain. In severe cases it may cause
urticaria
Hives, also known as urticaria, is a kind of skin rash with red, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and does not leave any long-lasti ...
, and the lymph glands under the arms may swell and become painful, and there have been rare cases of hospitalisation.
Mechanism
![Urtica stinging hair](https://upload.wikimedia.org/wikipedia/commons/8/8a/Urtica_stinging_hair.svg)
Very fine, brittle hairs (called
trichome
Trichomes (); ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a pla ...
s) loaded with toxins cover the entire plant; even the slightest touch will embed them in the skin.
Electron micrograph
A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an object. This is opposed to a macrograph or photomacrograph, an image which is also taken on a mi ...
images show that they are similar to a
hypodermic needle
A hypodermic needle (from Greek ὑπο- (''hypo-'' = under), and δέρμα (''derma'' = skin)), one of a category of medical tools which enter the skin, called sharps, is a very thin, hollow tube with one sharp tip. It is commonly used w ...
in being very sharp-pointed and hollow. Additionally, it has been shown that there is a structurally weak point near the tip of the hair, which acts as a pre-set fracture line. When it enters the skin the hair fractures at this point, allowing the contents of the trichome to be injected into the victim's tissues.
The trichomes stay in the skin for up to a year, and release the toxin cocktail into the body during triggering events such as touching the affected area, contact with water, or temperature changes. Ernie Rider, a conservation officer with the
Queensland Parks and Wildlife Service
The Queensland Parks and Wildlife Service (QPWS) is a business division of the Department of Environment and Science within the Government of Queensland. The division’s primary concern is with the management and maintenance of protected areas ...
, was slapped in the face and torso with the foliage in 1963, and said:
For two or three days the pain was almost unbearable; I couldn't work or sleep... I remember it feeling like there were giant hands trying to squash my chest... then it was pretty bad pain for another fortnight or so. The stinging persisted for two years and recurred every time I had a cold shower...There's nothing to rival it; it's ten times worse than anything else.
Physical contact with ''Dendrocnide moroides'' is not the only way that it can cause harm to a person—the trichomes are constantly being shed from the plant and may be suspended in the air within its vicinity. They can then be inhaled, which may lead to respiratory complications if a person spends time in close proximity to the plant. The Australian
entomologist
Entomology () is the scientific study of insects, a branch of zoology. In the past the term "insect" was less specific, and historically the definition of entomology would also include the study of animals in other arthropod groups, such as arach ...
and
ecologist
Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...
Marina Hurley wrote her
doctorate
A doctorate (from Latin ''docere'', "to teach"), doctor's degree (from Latin ''doctor'', "teacher"), or doctoral degree is an academic degree awarded by universities and some other educational institutions, derived from the ancient formalism ''l ...
studying two ''Dendrocnide'' species of the
Atherton Tablelands
The Atherton Tableland is a fertile plateau which is part of the Great Dividing Range in Queensland, Australia.
The principal river flowing across the plateau is the Barron River. It was dammed to form an irrigation reservoir named Lake Tinar ...
, west of
Cairns
Cairns (, ) is a city in Queensland, Australia, on the tropical north east coast of Far North Queensland. The population in June 2019 was 153,952, having grown on average 1.02% annually over the preceding five years. The city is the 5th-most-p ...
, namely ''Dendrocnide moroides'' and ''
Dendrocnide cordifolia'', and was exposed to the airborne hairs over a long period of time. She suffered sneezing fits, watery eyes and nose, and eventually developed an allergy that required medical attention.
W.V. MacFarlane, who was a Professorial Fellow in Physiology at the
John Curtin School of Medical Research
The John Curtin School of Medical Research (JCSMR) is an Australian multidisciplinary translational medical research institute and postgraduate education centre that forms part of the Australian National University (ANU) in Canberra. The school w ...
at the
Australian National University
The Australian National University (ANU) is a public research university located in Canberra, the capital of Australia. Its main campus in Acton encompasses seven teaching and research colleges, in addition to several national academies and ...
, observed the effects of inhaling the trichomes, and he reported:
The plucking of hairs from the leaves invariably produces sneezing in the operator within 10 or 15 minutes. During early attempts to separate stinging hairs from dried leaves, dust and presumably some hairs were inhaled. Initially they produced sneezing, but within three hours there was diffuse nasopharyngeal
The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struct ...
pain, and after 26 hours a sensation of an acute sore throat like tonsillitis
Tonsillitis is inflammation of the tonsils in the upper part of the throat. It can be acute or chronic. Acute tonsillitis typically has a rapid onset. Symptoms may include sore throat, fever, enlargement of the tonsils, trouble swallowing, and en ...
was experienced.
Pharmacology
The cause of the intense pain has been the subject of scientific research since European explorers first encountered the plant in the mid-19th century. While it is known that a cocktail of toxins is contained within the trichomes, its exact nature was not fully understood . It is known that the active constituents are very stable, since dead leaves found on the forest floor and even decades-old laboratory specimens can still inflict the sting.
Early studies suggested that a variety of compounds, such as
histamine
Histamine is an organic nitrogenous compound involved in local immune responses, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Since histamine was discovered in ...
,
acetylcholine
Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Part ...
,
5-hydroxytryptamine
Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vas ...
and
formic acid
Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Es ...
, could be responsible; however none of these has been proven to produce a similar intensity or duration of pain to those exhibited by the sting from the plant. Around 1970 a new compound was identified and given the name
moroidin. It was for a time thought possibly to be the causative agent; however later research showed that it did not cause the same effects as a sting from the plant.
In 2020 a previously unknown family of disulfide-rich peptides was identified by a group of researchers and given the name
gympietides. These compounds were shown to produce significant pain responses in laboratory tests. Moreover, their complex structure resembling the
inhibitor cystine knot
An inhibitor cystine knot (aka ICK or Knottin) is a protein structural motif containing three disulfide bridges. Knottins are one of three folds in the cystine knot motif; the other closely related knots are the Growth Factor Cystine Knot (GFCK) ...
made them highly stable, explaining how the sting lasts for such a long time.
There has been anecdotal evidence of some plants having no sting but still possessing the hairs, suggesting a chemical change to the toxin.
Remedies
A commonly recommended first-aid treatment is to use depilatory wax or
sticky tape
Sticky may refer to:
People
*Sticky (musician), alias of UK garage producer Richard Forbes
*Sticky Fingaz or Sticky (born 1973), nickname of the US rapper and actor Kirk Jones
Adhesion
*Adhesion, the tendency of dissimilar particles or surfaces t ...
to remove the hairs. The
Kuku Yalanji
The Kuku Yalanji, also known as Gugu-Yalanji, Kuku Yalandji or Kokojelandji, are an Aboriginal Australian people originating from the rainforest regions of Far North Queensland.
Language
The traditional language of the people is Guugu Yaland ...
people of
Mossman Gorge
Mossman Gorge is a rural locality in the Shire of Douglas, Queensland, Australia. In the , Mossman Gorge had a population of 246 people.
The locality takes its name from the valley Mossman Gorge created by the Mossman River through the Daintree ...
used a method that was essentially similar, making a juice from the fruits or roots of the plant and applying it to the affected area, before scraping it off with a mussel shell once it had become sticky. Mechanical removal is not always successful however, as the hairs are so tiny that the skin will often close over them, making removal impossible.
Various other treatments, mostly ineffectual, have been tried over time. They include bathing the affected area in hot water, applying
papaya
The papaya (, ), papaw, () or pawpaw () is the plant species ''Carica papaya'', one of the 21 accepted species in the genus ''Carica'' of the family Caricaceae. It was first domesticated in Mesoamerica, within modern-day southern Mexico and ...
ointment, xylocaine or lignocaine cream, and even swabbing with dilute
hydrochloric acid
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid
Acid strength is the tendency of an acid, symbol ...
. All of these have, at best, temporary effect.
Anecdotal stories
Anecdotes of encounters with Gympie-gympie are numerous, and many can be dismissed as
yarns
Yarn is a long continuous length of interlocked fibres, used in sewing, crocheting, knitting, weaving, embroidery, ropemaking, and the production of textiles. Thread is a type of yarn intended for sewing by hand or machine. Modern manuf ...
, such as one which involves using the leaves as toilet paper (the user would have been stung when they first picked up the leaf, and unlikely to have proceeded to use it in the intended manner). Nevertheless, some have been documented, such as horses having to be rested after being stung, or even becoming violent and having to be shot. Only one report of a human fatality attributed to any ''Dendrocnide'' species (in this case ''D. cordata'') is confirmed, which occurred in
New Guinea
New Guinea (; Hiri Motu
Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea).
It is a simplified version of ...
in 1922.
Gallery
File:Dendrocnide moroides shrub SF20326.jpg, Mature shrub around 3 metres tall
File:Dendrocnide moroides (Gympie Gympie) 4.jpg , Inflorescence
File:Stinging tree.JPG , Foliage
File:Dendrocnide moroides (Gympie Gympie) 5.jpg , Detail showing stinging hairs
File:Dendrocnide moroides fruits SF21168.jpg, Fruits and leaves
References
External links
Map of observationsof ''Dendrocnide moroides'' at the
Australasian Virtual Herbarium
The ''Australasian Virtual Herbarium'' (AVH) is an online resource that allows access to plant specimen data held by various Australian and New Zealand herbaria. It is part of the Atlas of Living Australia (ALA), and was formed by the amalgamat ...
.
Queensland’s Gympie-Gympie: the world’s most painful plant John Oxley Library Blog, State Library of Queensland.
{{Taxonbar, from=Q782859
Bushfood
Dendrocnide
Flora of New South Wales
Flora of Queensland
Flora of the Maluku Islands
Flora of the Lesser Sunda Islands
Rosales of Australia
Poisonous plants