Poisonous plants

This article was originally written by Miles and has been reposted by Ethan

http://en.wikipedia.org/wiki/List_of_poisonous_plants for the full list.

Some notable poisonous plants:

• Apple (Malus domestica). Seeds are mildly poisonous, containing a small amount of amygdalin, a cyanogenic glycoside. The quantity contained is usually not enough to be dangerous to humans, but it is possible to ingest enough seeds to provide a fatal dose.
• Cherry (Prunus cerasus), as well as other Prunus species such as peach (Prunus persica), plum (Prunus domestica), almond (Prunus dulcis), andapricot (Prunus armeniaca). Leaves and seeds contain cyanogenic glycosides.
• Kidney bean or common bean (Phaseolus vulgaris). The toxic compound phytohaemagglutinin, a lectin, is present in many varieties of common bean but is especially concentrated in red kidney beans. The lectin has a number of effects on cell metabolism; it induces mitosis, and affects the cell membrane in regard to transport and permeability to proteins. It agglutinates most mammalian red blood cell types. The primary symptoms of phytohaemagglutinin poisoning are nausea, vomiting, and diarrhea. Onset is from 1 to 3 hours after consumption of improperly prepared beans, and symptoms typically resolve within a few hours.[10] Consumption of as few as four or five raw kidney beans may be sufficient to trigger symptoms. Phytohaemagglutinin can be deactivated by cooking beans at 100 °C (212 °F) for ten minutes. However, for dry beans the U.S. Food and Drug Administration (FDA) also recommends an initial soak of at least 5 hours in water; the soaking water should be discarded.[10] The ten minutes at 100 °C (212 °F) is required to degrade the toxin, and is much shorter than the hours required to fully cook the beans themselves. However, lower cooking temperatures may have the paradoxical effect of potentiating the toxic effect of haemagglutinin. Beans cooked at 80 °C (176 °F) are reported to be up five times as toxic as raw beans.[10] Outbreaks of poisoning have been associated with the use of slow cookers, the low cooking temperatures of which may be unable to degrade the toxin.
• Nutmeg (Myristica fragrans). Contains myristicin. Myristicin is a naturally occurring insecticide and acaricide with possible neurotoxic effects onneuroblastoma cells.[11] It has psychoactive properties at doses much higher than used in cooking. Raw nutmeg produces anticholinergic-like symptoms, attributed to myristicin and elemicin.[12] The intoxicating effects of myristicin can lead to a physical state somewhere between waking and dreaming; euphoria is reported and nausea is often experienced. Users also report bloodshot eyes and memory disturbances.[13] Myristicin is also known to induce hallucinogenic effects, such as visual distortions. Nutmeg intoxication has an extremely long time before peak is reached, sometimes taking up to seven hours, and effects can be felt for 24 hours, with lingering effects lasting up to 72 hours.[14][15]
• Lima bean or butter bean (Phaseolus lunatus). Raw beans contain dangerous amounts of linamarin, a cyanogenic glucoside.
• Potato (Solanum tuberosum). Potatoes contain toxic compounds known as glycoalkaloids, of which the most prevalent are solanine and chaconine. Solanine is also found in other members of the Solanaceae plant family, which includes Atropa belladonna ("deadly nightshade") and Hyoscyamus niger("henbane") (see entries below). The concentration of glycoalkaloid in wild potatoes suffices to produce toxic effects in humans. The toxin affects the nervous system, causing headaches, diarrhea and intense digestive disturbances, cramps, weakness and confusion, and in severe cases coma and death. Poisoning from cultivated potatoes occurs very rarely however, as the toxic compounds in the potato plant are, in general, concentrated in the green portions of the plant and in the fruits,[16] and cultivated potato varieties contain lower toxin levels.[17] Cooking at high temperatures (over 170 °C or 340 °F) also partly destroys the toxin. However, exposure to light, physical damage, and age increase glycoalkaloid content within the tuber,[18] the highest concentrations occurring just underneath the skin. Tubers that are exposed to light turn green from chlorophyll synthesis, thus giving a visual clue as to areas of the tuber that may have become more toxic; however, this does not provide a definitive guide, as greening and glycoalkaloid accumulation can occur independently of each other. Some varieties of potato contain greater glycoalkaloid concentrations than others; breeders developing new varieties test for this, and sometimes have to discard an otherwise promising cultivar. Breeders try to keep solanine levels below 200 mg/kg (200 ppmw). However, when these commercial varieties turn green, even they can approach concentrations of solanine of 1000 mg/kg (1000 ppmw). The U.S. National Toxicology Program suggests that the average American consume at most 12.5 mg/day of solanine from potatoes (the toxic dose is actually several times this, depending on body weight).
• Rhubarb (Rheum rhaponticum). The leaf stalks (petioles) are edible, but the leaves themselves contain notable quantities of oxalic acid, which is anephrotoxic and corrosive acid that is present in many plants. Symptoms of poisoning include kidney disorders, convulsions and coma. Rarely fatal. TheLD50 (median lethal dose) for pure oxalic acid in rats is about 375 mg/kg body weight,[19] or about 25 grams for a 65 kg (~140 lb) human. Although the oxalic acid content of rhubarb leaves can vary, a typical value is about 0.5%,[20] so a rather unlikely 5 kg of the extremely sour leaves would have to be consumed to reach an LD50 of oxalic acid. Cooking the leaves with soda can make them more poisonous by producing soluble oxalates.[21] However, the leaves are believed to also contain an additional, unidentified toxin,[22] which might be an anthraquinone glycoside (also known as senna glycosides).[23] In the edible leaf stalks (petioles), the amount of oxalic acid is much lower, only about 2–2.5% of the total acidity that is dominated bymalic acid.[24] This means that even the raw stalks may not be hazardous (though they are generally thought to be in the US). However the tart taste of raw stalks is so strong as to be unpalatable to many.
• Tomato (Solanum lycopersicum). Like many other nightshades, tomato leaves and stems contain solanine that is toxic if ingested, causing digestive upset and nervous excitement. Use of tomato leaves as an herbal tea (infusion) has been responsible for at least one death.[25] Leaves, stems, and green unripe fruit of the tomato plant also contain small amounts of the poisonous alkaloid tomatine,[26] although levels are generally too small to be dangerous.[26][27] Ripe tomatoes do not contain any detectable tomatine.[26] Tomato plants can be toxic to dogs if they eat large amounts of the fruit, or chew plant material.[28]

Cerbera odollam (commonly known as the suicide tree). The seeds contain cerberin, a potent toxin related to digoxin. The poison blocks the calciumion channels in heart muscle, causing disruption of the heart beat. This is typically fatal and can result from ingesting a single seed. Cerberin is difficult to detect in autopsies and its taste can be masked with strong spices, such as a curry. It is often used in homicide and suicide in India; Kerala's suicide rate is about three times the Indian average. In 2004, a team led by Yvan Gaillard of the Laboratory of Analytical Toxicology in La Voulte-sur-Rhône, France, documented more than 500 cases of fatal Cerbera poisoning between 1989 and 1999 in Kerala. They said "To the best of our knowledge, no plant in the world is responsible for as many deaths by suicide as the odollam tree.'[41] A related species is Cerbera tanghin the seeds of which are known as tanghin poison nut and have been used as an 'ordeal poison'.