Dendrocnide moroides
Encyclopedia
Dendrocnide moroides, also known as the Gympie Gympie, moonlighter, or stinger, is a large shrub native to rainforest areas in northeastern Australia
, the Moluccas and Indonesia
. It is best known for stinging hairs which cover the whole plant and deliver a potent neurotoxin
when touched. It is the most virulent species of stinging tree.
D. moroides usually grows as a single-stemmed plant reaching 1–2 metres in height. It has large, heart-shaped leaves that are about 12–22 cm long and 11–18 cm wide, with finely toothed margins.
in having bisexual inflorescence
s in which the few male flowers are surrounded by female flowers. The flowers are small, and once pollinated the stalk swells to form the fruit. Fruits are juicy and mulberry
-like and are bright pink to purple. Each fruit contains a single seed which is on the outside of the fruit.
The species is an early coloniser in rainforest gaps; seeds germinate in full sunlight after soil disturbance. Although relatively common in Queensland
, the species is uncommon in its southern-most range, and is listed as an endangered species in New South Wales
.
The giant stinging tree
and the shining-leaved stinging tree
are other large nettles
occurring in Australia.
species, including the Red-legged Pademelon
, insects and birds from eating the leaves. Moroidin, a bicyclic octapeptide
containing an unusual C-N linkage between tryptophan
and histidine
, was first isolated from the leaves and stalks of Dendrocnide moroides and subsequently shown to be the principle responsible for the long duration of the stings.
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, the Moluccas and Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. It is best known for stinging hairs which cover the whole plant and deliver a potent neurotoxin
Neurotoxin
A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...
when touched. It is the most virulent species of stinging tree.
D. moroides usually grows as a single-stemmed plant reaching 1–2 metres in height. It has large, heart-shaped leaves that are about 12–22 cm long and 11–18 cm wide, with finely toothed margins.
Ecology
The species is unique in the genusDendrocnide
Dendrocnide is a genus of 37 species of shrub to large tree in the nettle family Urticaceae. They have a wide distribution across South-East Asia, Australia and the Pacific Islands.They are colloquially known as stinging nettles or nettle trees...
in having bisexual inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s in which the few male flowers are surrounded by female flowers. The flowers are small, and once pollinated the stalk swells to form the fruit. Fruits are juicy and mulberry
Mulberry
Morus is a genus of flowering plants in the family Moraceae. The 10–16 species of deciduous trees it contains are commonly known as Mulberries....
-like and are bright pink to purple. Each fruit contains a single seed which is on the outside of the fruit.
The species is an early coloniser in rainforest gaps; seeds germinate in full sunlight after soil disturbance. Although relatively common in Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, the species is uncommon in its southern-most range, and is listed as an endangered species in New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
.
The giant stinging tree
Dendrocnide excelsa
Dendrocnide excelsa, the giant stinging tree is a rainforest tree of eastern Australia. It occurs from Tathra, New South Wales to Imbil in south eastern Queensland, and is very common at Dorrigo National Park and other rainforest walks in eastern Australia...
and the shining-leaved stinging tree
Dendrocnide photinophylla
Dendrocnide photinophylla, the shining-leaved stinging tree, is a rainforest tree of eastern Australia. It occurs from near the Colo River north west of Sydney to Cooktown in tropical Queensland. A versatile species occurring in many different rainforest types. The specific epithet photinophylla...
are other large nettles
Urticaceae
Urticaceae, or the nettle family, is a family of flowering plants. The family name comes from the genus Urtica . Urticaceae includes a number of well-known and useful plants, including the aforementioned nettles, Ramie , māmaki , and ajlai .The family includes approximately 2600 species, grouped...
occurring in Australia.
Toxicity
Contact with the leaves or twigs causes the hollow silica-tipped hairs to penetrate the skin. The sting causes a painful stinging sensation which can last for days or even months, and the injured area becomes covered with small red spots joining together to form a red, swollen mass. The sting is known to be potent enough to kill humans, and it can also kill dogs and horses. However the sting does not stop several small marsupialMarsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
species, including the Red-legged Pademelon
Red-legged Pademelon
The Red-legged Pademelon 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 around Tamworth in New South Wales...
, insects and birds from eating the leaves. Moroidin, a bicyclic octapeptide
Peptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
containing an unusual C-N linkage between tryptophan
Tryptophan
Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...
and histidine
Histidine
Histidine Histidine, an essential amino acid, has a positively charged imidazole functional group. It is one of the 22 proteinogenic amino acids. Its codons are CAU and CAC. Histidine was first isolated by German physician Albrecht Kossel in 1896. Histidine is an essential amino acid in humans...
, was first isolated from the leaves and stalks of Dendrocnide moroides and subsequently shown to be the principle responsible for the long duration of the stings.
External links
- Dendrocnide at Department of Biology, Davidson CollegeDavidson CollegeDavidson College is a private liberal arts college in Davidson, North Carolina. The college has graduated 23 Rhodes Scholars and is consistently ranked in the top ten liberal arts colleges in the country by U.S. News and World Report magazine, although it has recently dropped to 11th in U.S. News...