Top 5 Most Poisonous Plants

Posted: 12/03/2008 01:46:00 pm
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Author: Java[at]Saindra
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Filed under: informasi, information, plants

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A carnivorous pitcher plant
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In the mid-1800s, the story of a man-eating tree captured widespread attention. In a report he wrote for the South Australian Register, Carl Liche, a German explorer, claimed that while exploring Madagascar, he'd witnessed a woman climb the trunk of a large plant and drink its nectar. When the plant sensed her presence, it captured her with its tentacles and pulled her into its body.

One hundred years later, a 1950s science writer debunked the legend, asserting that not only was there no such tree, but that no one by name of Carl Liche had ever explored Madagascar.

While a tentacle-wielding, man-consuming tree may not exist, a scaled-down version of such a plant does. The man-eating tree of Madagascar may have been an exaggeration of the pitcher plants that grow in Madagascar, Indonesia, Australia, Malaysia and other hot and humid, low-lying areas. The largest of the pitcher plants is known as Nepenthes, and this plant does capture small vermin and lizards in its pitchers (or flowers).

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The pitcher plant creates a substance within its leaves that coats the inside of its pitcher-shaped flowers. This substance mixes with water that the plant draws up through its roots. Insects and, on occasion, small animals are attracted to the scented water. When they come to drink, they fall into the pitcher, are unable to escape, and the plant draws nutrients from the captured prey.

While you certainly won't fall prey to the pitchers of the Nepenthes -- they're entirely too small to hold a human -- you could easily fall prey to the sickness some plants induce. In fact, the following five could actually kill you.

Poisonous Plant Number 5: The Castor Bean

The castor bean plant, or Ricinus communis, is widely cultivated for its castor oil and is also used as an ornamental plant. Neither of these uses would clue you into the fact that this plant has deadly contents: ricin.

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Castor bean plants are cultvated for their oil, but their seeds also contain a deadly poison -- ricin.

Castor oil is a mild-tasting vegetable oil that is used in many food additives, flavorings and in candy production. It's also available to the consumer as a laxative and to induce labor (though no scientific evidence shows it's successful in inducing labor). Castor oil comes from the plant's seeds, which are 40 to 60 percent oil.

The castor bean plant probably originated in Africa, but is now found throughout the world. This large, shrubby plant is popularly used in gardens because of its hardy nature. It grows well in barren areas and doesn't require special care. It's fast-growing and can reach 36 feet (11 meters) in a season. The flowers of the plant are yellowish green, and the centers of the flowers are red. The leaves are large with toothed edges.

Ricin is present in low levels throughout the plant, but it is largely concentrated in the seed coating. Seed poisonings are rare and usually involve children and pets, but they can be deadly. As few as three seeds, which are green with brown markings, could kill a child who swallows them.

Symptoms of castor bean poisoning include nausea, abdominal cramps, vomiting, internal bleeding, and kidney and circulation failure. Many people suffer from an allergic reaction to the dust from the seeds and may experience coughing, muscle aches and difficulty breathing. Exposure to the dust is most common in areas where the beans are processed for commercial use. In ancient times, the castor bean was used in ointments, and allegedly, Cleopatra applied the oil to the whites of her eyes to brighten them.

All-natural Murder
Well-known Bulgarian writer Georgi Markov defected from Bulgaria in 1969, when Bulgaria was still a Communist state. Once he settled in England, he took a job as a journalist and broadcaster for BBC World Service and Radio Free Europe. Bulgarian government officials were not pleased when Markov developed a broadcast titled "In Absentia -- Reports" about life in Communist Bulgaria. So they made arrangements to silence him for good.

As Markov stood at the bus stop one day, he felt a sharp jab in the back of his leg. When he turned, a man apologized for poking him with his umbrella. Three days later, Markov was dead. During an autopsy, physicians removed a metal pellet the size of a pin head from Markov's calf. The pellet was hollow in the center and contained traces of ricin [source: Center for Disease Control].

Poisonous Plant Number 4: Deadly Nightshade

The name says it all. Deadly nightshade, or Atropa belladonna, contains poisonous atropine and scopolamine in its stems, leaves, berries and roots.

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These leaves may look harmless enough, but don't you dare take a bite.

Deadly nightshade is a perennial plant that grows between 2 and 4 feet (0.6 to 1.2 meters) tall. You'll recognize it by its dull, dark green leaves and bell-shaped purple, scented flowers, which bloom from mid-summer through early fall. Deadly nightshade berries are green when they form and turn to a shiny black as they ripen. They're sweet and juicy, which makes them tempting to children. The plant requires rich, moist soil to thrive, and it grows wild in some areas of the world, but in the U.S. is limited to cultivation. Not all animals are affected by deadly nightshade. While it's deadly to humans and some animals, horses, rabbits and sheep can eat the leaves without harm, and birds feed on the berries.

The poisons contained in deadly nightshade affect the nervous system. Taken in sufficient doses, the deadly poison paralyzes nerve endings in the involuntary muscles of the body, such as the blood vessels, heart and gastrointestinal muscles. Symptoms of deadly nightshade poisoning include dilated pupils, sensitivity to light, blurred vision, headaches, confusion and convulsions. As few as two ingested berries can kill a child, and 10 to 20 berries would kill an adult. Even handling the plant can cause irritation.

Legend has it that women in Italy put deadly nightshade juice in their eyes to brighten them [source: Georgetown Pharmacology]. In fact, one of the common names for deadly nightshade is belladonna, which is Italian for "beautiful lady." Today, doctors rarely perform any type of eye surgery without using atropine, one of the poisons in deadly nightshade, to dilate the patient's pupils.

Poisonous Plants at the Garden Center
If you think the only way to find a poisonous plant is to visit the jungles of South America or the tropical zones of Africa, you're mistaken. You'll find plants that could make you seriously ill or even kill you at your local garden center. Plants with innocent-sounding names, like cardinal flower and angel's trumpet, could send you to the hospital. Ingesting cardinal's flower's leaves or blooms can cause extreme gastrointestinal distress, and the angel's trumpet's leaves and blooms can cause terrifying hallucinations.

Poisonous Plant Number 3: Rosary Pea

The rosary pea, or Abrus precatorius, has very pretty seeds. Two-thirds of the seed is red, and the top third is black. These decorative seeds are often used to make jewelry, and that jewelry is imported to other countries. In fact, these seeds are especially popular for rosary prayer beads.

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Rosary necklaces are sometimes strung with rosary pea seeds.

But rosary pea seeds contain the poison abrin. The seeds are only dangerous when the coating is broken -- swallowed whole, the rosary pea doesn't present any danger. But if the seed is scratched or damaged, it's deadly. The rosary pea poses greater danger to the jewelry maker than to the wearer. There are many reported cases of death when jewelry makers prick a finger while handling the rosary pea.

Rosary pea plant is an aggressive grower and can take over an area if not kept in check. One rosary pea vine can grow and climb over 20 feet (6 meters) in a single season. The plant, which is native to Indonesia, has spread across the world, in tropic and sub-tropic climates. It's even located in several states in the United States, including Alabama, Arkansas, Florida, Georgia and Hawaii. The plant has long leaves with off-shooting leaflets and red flowers.

Abrin, the poison found in the rosary pea seed, is more deadly than ricin. Less than 3 micrograms of abrin in the body is enough to kill, which is less than the amount of poison in one pea. In the human body, abrin bonds to cell membranes and prevents protein synthesis, one of the most important duties of the cell. Symptoms of rosary pea inhalation poisoning are: difficult breathing, fever, nausea and fluid in the lungs. If ingested -- and the seed coating is broken -- rosary pea seeds cause severe nausea and vomiting, which eventually leads to dehydration, and ends with the kidneys, liver and spleen shutting down. Death usually follows within three to four days.

Using Deadly Plants as Medicine
It seems counterintuitive to put deadly plants to work at saving lives. But some of the most deadly plants are used in the medical arena. Jimsonweed, for example, has been used by hired assassins to kill people and by doctors to treat epilepsy. Other contenders?

Castor bean plant is used in Paclitaxel, a chemotherapy drug, in Sandimmune, a drug for immune suppression, and in Xenaderm, a topical treatment for skin ulcers.
Scopolamine, one of the poisons found in deadly nightshade, was combined with morphine as early as 1902 and used to induce "twilight sleep" during childbirth.
Quinine, the long-standing treatment for malaria and internal parasites, is derived from the bark of the cinchona tree. It's deadly if consumed in large amounts.

Poisonous Plant Number 2: Water Hemlock

The water hemlock, or cicuta maculata, is a very attractive wildflower with an upright growth pattern, purple-striped leaves and small white blooms. But the water hemlock's white roots are sometimes mistaken for a parsnip plant -- a potentially fatal error. The poison contained in the water hemlock, cicutoxin, is present in the entire plant, but is most concentrated in the roots. Anyone who confuses the plant with parsnips and decides to take a bite faces a violent death.

The water hemlock, which is native to North America, is considered by many to be the most deadly plant on the continent. The wildflower, which grows to 6 feet (1.8 meters), thrives along stream banks, in marshy areas, and in low-lying, damp meadows.

For those unlucky enough to taste the water hemlock, the onset of illness is rapid. The cicutoxin contained in the plant causes violent and painful convulsions, nausea, vomiting, cramps and muscle tremors. Those who survive the poisoning experience long-term health conditions, such as amnesia. No amount of water hemlock root is considered safe to ingest.

Plants that Attack
It seems impossible that a plant, rooted to one spot, could attack. But several species of stinging trees, indigenous to rainforest areas of Australia and Indonesia, certainly make victims feel that they've been assaulted. These plants, which range from overgrown shrubs to full-sized trees, have glass-like hairs covering their leaves and fruits.

When a person brushes up against the plant, those hairs become dislodged and imbedded in the person's skin. The hair, once under your skin, releases a neurotoxin that causes pain. Neurotoxins are poisons that work specifically on the nerve cells in the body. The pain gradually subsides but can reoccur intermittently for several months. There's one confirmed death due to stinging tree, and other anecdotes of victims, particularly World War II soldiers, shooting themselves to escape the pain.

Poisonous Plant Number 1: Oleander

The oleander, or Nerium oleander, is considered by many to be the most poisonous plant in the world. All parts of the beautiful oleander contain poison -- several types of poison. Two of the most potent are oleandrin and neriine, known for their powerful effect on the heart. An oleander's poison is so strong, in fact, that it can poison a person who simply eats the honey made by bees that have digested oleander nectar.

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Oleander flowers are beautiful, but don't be deceived -- this plant is deadly.

The oleander is an attractive plant, and despite its deadly reputation is often planted for decorative purposes. Although native to the Far East and the Mediterranean areas, oleander has been introduced in the United States, where it grows easily. It's tolerant of poor quality soil and dry weather. The plant grows as a dense shrub, and is typically 6 to 18 feet (1.8 to 5.4 meters) tall at maturity. It has thick, dark green leaves, and the flowers, which grow in clusters, can be yellow, red, pink or white.

Even in barren areas, the oleander produces lovely flowers and fragrance. Animals instinctively avoid the plant, and it grows rapidly, so it's often used for highway barriers and other areas that require screening from noise and pollution. Its rapid growth also makes it a popular choice around new construction zones, as it prevents erosion.

Unlike some toxic plants, the oleander is poisonous to most animals as well as humans. A single ingested oleander leaf can kill a child. Ingestion of oleander results in diarrhea, vomiting, intense stomach pain, drowsiness, dizziness, an irregular heartbeat, and often, death. If the victim survives the initial 24 hours after ingestion, his or her odds of surviving increase dramatically. For successful treatment, the patient is induced to vomit, his or her stomach may be pumped, or he or she may be fed activated charcoal to absorb as much of the poison as possible.

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