Difference between revisions of "Nerium oleander"

Latest revision as of 11:27, 7 July 2010

Nerium oleander (pronounced /ˈnɪəriəm ˈoʊliː.ændər/),^[2] is an evergreen shrub or small tree in the dogbane family Apocynaceae. It is the only species currently classified in the genus Nerium. It is most commonly known as Oleander but has many other names.^[3] The ancient city of Volubilis in Morocco took its name from the old Latin name for the flower. Oleander is one of the most poisonous of commonly grown garden plants, and can be very toxic if ingested in sufficient quantity.

Description

Oleander grows to 2–6 m (6.6–19.7 ft) tall, with spreading to erect branches. The leaves are in pairs or whorls of three, thick and leathery, dark green, narrow lanceolate, 5–21 cm (2.0–8.3 in) long and 1–3.5 cm (0.39–1.38 in) broad, and with an entire margin. The flowers grow in clusters at the end of each branch; they are white, pink, red or yellow, 2.5–5 cm (0.98–1.97 in) diameter, with a deeply 5-lobed corolla with a fringe round the central corolla tube. They are often, but not always, sweetly scented. The fruit is a long narrow capsule 5–23 cm (2.0–9.1 in) long, which splits open at maturity to release numerous downy seeds.

In the past, scented plants were sometimes treated as the distinct species N. odorum, but the character is not constant and it is no longer regarded as a separate taxon.

Habitat and range

N. oleander is native to a broad area from Morocco and Portugal eastward through the Mediterranean region and southern Asia to Yunnan in southern parts of China.^{[4][5] [6][7]} It typically occurs around dry stream beds.

Uses

Ornamental

Oleander grows well in warm subtropical regions, where it is extensively used as an ornamental plant in landscapes, parks, and along roadsides. It is drought tolerant and will tolerate occasional light frost down to −10 °C (14 °F).^[7] It is commonly used in landscaping freeway medians in California and other mild-winter states in the Continental United States because it is easily maintained. It is deer resistant and tolerant of poor soils and drought. Oleander can also be grown in cooler climates in greenhouses and conservatories, or as indoor plants that can be kept outside in the summer. Oleander flowers are showy and fragrant and are grown for these reasons. Over 400 cultivars have been named, with several additional flower colours not found in wild plants having been selected, including red, purple, pink and orange; white and a variety of pinks are the most common. Many cultivars also have double flowers. Young plants grow best in spaces where they do not have to compete with other plants for nutrients.

Medicinal

Pliny the Elder in his Naturalis Historia written circa AD 77 claimed that despite its toxicity Oleander was an effective snakebite cure: "...if taken in wine with rue...".^[8]

Despite a lack of any proven benefits,^[9] a range of Oleander-based treatments are being promoted on the Internet and in some alternative medicine circles, drawing a warning letter from the U.S. Food and Drug Administration (FDA).^[10] Additionally, a Texas-based biotechnology company is researching oleander as a potential treatment for skin cancers and as well as an anti-viral treatment.^[11]

Toxicity

Oleander is one of the most poisonous plants in the world and contains numerous toxic compounds, many of which are deadly to people, especially young children. (Despite this fact, it is often grown in school yards.^[12]) The toxicity of Oleander is considered extremely high, and it has been reported that in some cases only a small amount had lethal or near-lethal effects.^[13] The most significant of these toxins are oleandrin and neriine, which are cardiac glycosides.^[13] They are present in all parts of the plant, but are most concentrated in the sap, which can block out receptors. High risk circumstances of exposure include children playing with the ornamental shrub, as well as adults or children tasting, chewing, ingesting portions of the plant [1], and inappropriate medicinal use of plant infusion.^[6] Oleander bark contains rosagenin which is known for its strychnine-like effects. The entire plant, including the nectar,^[14] is toxic, and any part can cause an adverse reaction. Oleander is also known to hold its toxicity even after drying. It is thought that a handful or 10-20 leaves consumed by an adult can cause an adverse reaction, and a single leaf could be lethal to an infant or child. According to the Toxic Exposure Surveillance System (TESS) in 2002 there were 847 exposures to Oleander reported to poison centers in the United States.^[15] There are innumerable reported suicidal cases of consuming mashed oleander seeds in southern India. Around 0.23 mg per pound of body weight is lethal to many animals, and various other doses will affect other animals. Most animals can suffer a reaction or death from this plant.^[6]

Effects of poisoning

Reactions to this plant are as follows: Ingestion can cause both gastrointestinal and cardiac effects. The gastrointestinal effects can consist of nausea and vomiting, excess salivation, abdominal pain, diarrhea that may or may not contain blood, and especially in horses, colic.^[6] Cardiac reactions consist of irregular heart rate, sometimes characterized by a racing heart at first that then slows to below normal further along in the reaction. The heart may also beat erratically with no sign of a specific rhythm. Extremities may become pale and cold due to poor or irregular circulation. Reactions to poisonings from this plant can also affect the central nervous system. These symptoms can include drowsiness, tremors or shaking of the muscles, seizures, collapse, and even coma that can lead to death. Oleander sap can cause skin irritations, severe eye inflammation and irritation, and allergy reactions characterized by dermatitis.^[13]

Medical treatment required

Poisoning and reactions to Oleander plants are evident quickly, requiring immediate medical care in suspected or known poisonings of both humans and animals.^[13] Induced vomiting and gastric lavage are protective measures to reduce absorption of the toxic compounds. Charcoal may also be administered to help absorb any remaining toxins.^[6] Further medical attention may be required and will depend on the severity of the poisoning and symptoms. Temporary cardiac pacing will be required in many cases (usually for a few days) till the toxin is excreted.

Digoxin Immune Fab is the best way to cure an oleander poisoning if inducing vomiting has no or minimal success, although it is usually only used for life-threatening conditions due to side effects.^{[citation needed]}

Drying of plant materials does not eliminate the toxins. It is also hazardous for animals such as sheep, horses, cattle, and other grazing animals, with as little as 100 g being enough to kill an adult horse.^[16] Plant clippings are especially dangerous to horses, as they are sweet. In July 2009, several horses were poisoned in this manner from the leaves of the plant.^[17] Symptoms of a poisoned horse include severe diarrhea and abnormal heartbeat. There are a wide range of toxins and secondary compounds within Oleander, and care should be taken around this plant due to its toxic nature. Different names for Oleander are used around the world in different locations, so when encountering a plant with this appearance, regardless of the name used for it, exercise great care and caution to avoid ingestion of any part of the plant, including its sap and dried leaves or twigs. Do not use the dried or fresh branches for spearing food, in preparing a cooking fire, or as a food skewer. Many of the Oleander relatives, such as the Desert Rose (Adenium obesum) found in East Africa, have similar leaves and flowers and are equally toxic.

Trunk oil

While the reasons are unknown, some visibly healthy oleander shrubs that have become sick or otherwise diseased may generate a type of oil from the trunk and shallow roots.^{[citation needed]} Depending upon the size of the shrub, the oil quantity can vary greatly and has the capability to saturate the soil in its vicinity as the shrub's sickness progresses. This is possibly an explanation for the plant's name of "Olea", whose Latin translation is "oil". The oil is light-brown colored and possesses a rancid scent. The toxicity of the oil is unknown, because the neuro-toxic chemicals in the rest of the tree come from the leaves vein-system and not from the pulp surrounding these veins.

Ecology

Some invertebrates are known to be unaffected by oleander toxins, and feed on the plants. Caterpillars of the Oleander or Polka-dot Wasp Moth (Syntomeida epilais) feed specifically on oleanders and survive by eating only the pulp surrounding the leaf-veins, avoiding the fibers. Larvae of the Oleander or Common Crow Butterfly (Euploea core) also feed on Oleanders. The Common Crow larvae retain or modify toxins, making them unpalatable to would-be predators such as birds, but apparently not to other invertebrates such as spiders and wasps.

Popular culture

In the novel Dragonwyck, the plant and its poisonous effect are essential to the plot. The plant can be seen in the film by the same name.

White Oleander is a 1999 book by Janet Fitch that was made into a 2002 drama film with the same name directed by Peter Kosminsky; poisoning using the oleander plant is central to the plot.

One story claims that some of Napoleon's soldiers in Spain died when they used oleander sticks to roast meat.^[18]

The legend of Chloe is possibly the most well known of the Myrtles Plantation's supposed ghosts; Chloe was a slave who was reputed to have killed her mistress and the mistress' two daughters by cooking a birthday cake poisoned with oleander.

Psybient artist Bluetech produced a track named "Oleander", which was also remixed by Phutureprimitive.

The title track from the rock band Phish album, Lawn Boy, mentions "...the black oleander surrounded by blues...".

The Canadian singer-songwriter Sarah Harmer's album I'm A Mountain contains a track titled "Oleander".

In the 95th episode of Monk, "Mr Monk and the Genius" ground up oleander bark is the method of poisoning the killer chooses to murder his wife.

Gallery

• MagentaOleanderFlower2000ppx.jpg

  A magenta flower.

• Oleander June 2007-1.jpg

  Expanding flower buds

• Frangipani3030.jpg

  Pink flowers

• Oleander Capsule Opens.jpg

  A seed capsule spreading seeds

• MagentaOleanderFlowers3800ppx.jpg

  Magenta flowers.

• NeriumOleander.jpg

  Bush without flowers.

• GroupMagentaOleanderFlowers3800ppx.jpg

  Bush in full bloom during the summer.

See also

• List of plants poisonous to equines
• List of poisonous plants

References

External links

• Clemson University: Oleander Facts. Retrieved on 2009-07-27.
• International Oleander Society: Information on Oleander toxicity. Retrieved on 2009-07-27.
• Barcelona Botanic Gardens: Plants of North Africa. Retrieved on 2009-07-27.
• Erwin, Van den Enden. 2004. Illustrated Lecture Notes on Tropical Medicine. Medical problems caused by plants: Plant Toxins, Cardiac Glycosides. Prince Leopold Institute of Tropical Medicine. Retrieved on 2009-07-27.
• Desai, Umesh R. Cardiac glycosides. Virginia Commonwealth University. School of Pharmacy. Retrieved on 2009-07-27.
• Snopes: Legend of Oleander-poisoning at Campfire. Retrieved on 2009-07-27.
• American Cancer Society: Oleander. Retrieved on 2009-07-27.
• Distribution over the world University of Helsinkiar:تفلة

bn:করবী bg:Зокум ca:Baladre cs:Oleandr obecný da:Nerie de:Oleander es:Nerium oleander eo:Oleandro fa:خرزهره fr:Laurier rose gl:Adelfa ko:협죽도 hi:कनेर hsb:Oleander id:Bunga jepun it:Nerium oleander he:הרדוף הנחלים ka:ოლეანდრე hu:Leander (növény) ml:അരളി nl:Oleander ja:キョウチクトウ no:Oleander nn:Oleander pnb:کنیر pl:Oleander pt:Oleandro ru:Олеандр sc:Oliandru simple:Oleander sl:Navadni oleander sr:Олеандер fi:Oleanteri sv:Oleander te:గన్నేరు th:ยี่โถ to:Lolie tr:Zakkum uk:Олеандр індійський vi:Trúc đào zh:夾竹桃

1. ↑ "Nerium oleander L". Germplasm Resources Information Network. United States Department of Agriculture. 1998-03-09. Retrieved 2010-06-26. 
2. ↑ Sunset Western Garden Book, 1995:606–607
3. ↑ Other names include Adelfa, Alheli Extranjero, Baladre, Espirradeira, Flor de São Jose, Cevadilha (Portuguese), Laurel de jardín, Laurel rosa, Laurier rose, Flourier rose, Olean, Aiwa, Rosa Francesca, Rosa Laurel, and Rose-bay (Inchem 2005), закум [zakum] (Bulgarian), leander (Hungarian), leandru (Romanian), zakum, zakkum, zakhum (Turkish), zaqqum (Arabic); harduf (Hebrew: הרדוף); Kaneru (Sinhalese);arali (Tamil and Malayalam - South Indian languages); kanagillu (Kannada - South Indian language); kaner (in Hindi, and, also, in Punjabi-the language from North Indian state of Punjab); and in Chinese it is known as jia zhu tao (
   中文:
   ).
4. ↑ Pankhurst, R. (editor). Nerium oleander L. Flora Europaea. Royal Botanic Garden Edinburgh. Retrieved on 2009-07-27.
5. ↑ Bingtao Li, Antony J. M. Leeuwenberg, and D. J. Middleton. Nerium oleander L. Flora of China. Harvard University. Retrieved on 2009-07-27.
6. ↑ ^{6.0 6.1 6.2 6.3 6.4} INCHEM (2005). Nerium oleander L. (PIM 366). International Programme on Chemical Safety: INCHEM. Retrieved on 2009-07-27
7. ↑ ^{7.0 7.1} Huxley, A.; Griffiths, M.; Levy, M. (eds.) (1992). The New RHS Dictionary of Gardening. Macmillan. ISBN 0-333-47494-5.
8. ↑ Perseus Digital Library: Pliny the Elder. Retrieved on 2009-07-27.
9. ↑ Phase I Study of Anvirzel^TM in Patients with Advanced Solid Tumors. American Society of Clinical Oncology. Retrieved on 2009-07-27.]
10. ↑ Food and Drug Administration: Anvirzel Letter, dated March 7, 2000. Retrieved on 2009-07-27.
11. ↑ http://www.nerium.com/index-2.html
12. ↑ [2] Encyclopedia of Stanford Trees, Shrubs, and Vines: Nerium oleander.
13. ↑ ^{13.0 13.1 13.2 13.3} Goetz, Rebecca. J. (1998). "Oleander". Indiana Plants Poisonous to Livestock and Pets. Cooperative Extension Service, Purdue University. Retrieved on 2009-07-27.
14. ↑ "Oleander poisoning". MedlinePlus. U.S. National Library of Medicine. Retrieved 2010-06-26. 
15. ↑ Watson, William A., et al. 2003. 2002 Annual Report of the American Association of Poison Control Centers Toxic Exposure Surveillance System. American Journal of Emergency Medicine 21 (5): 353-421.
16. ↑ Knight, A. P. (1999). "Guide to Poisonous Plants: Oleander". Colorado State University. Retrieved on 2009-07-27.
17. ↑ Trevino, Monica. 2009.Dozens of horses poisoned at California farm. CNN: Crime. Retrieved on 2009-08-03
18. ↑ John Lindley. 1853. The vegetable kingdom; or, The structure, classification, and uses of plants. page 600.