РефератыИностранный языкRhRhododendron Essay Research Paper RhododendronThe plant rhododendron

Rhododendron Essay Research Paper RhododendronThe plant rhododendron

Rhododendron Essay, Research Paper


Rhododendron


The plant rhododendron belongs to the family


Ericaceae which also includes the Heath, and there are


about eight-hundred fifty species which grow worldwide


(Turner and Szczawinski, 171-2). The Heath family is a


large one with so many species, all of the poisonous


species fall into two of its subfamilies, one of which is


the rhododendron.


These cultivated plants occur naturally in temperate


regions of the northern hemisphere and in the mountains of


Southeast Asia. They are located in the Himalayas with


seven-hundred species, southwest China, Burma, and in New


Guinea with over three-hundred species (Turner and


szczawinski, 172). It has been popular as ornaments in


gardens and has led to a major horticultural industry with


its widely uses in landscaping.


There are twenty-seven species native to North


America, (Turner,172) and is the state plant of


Washington. This specific plant is called R. macrophyllum


or the Pacific rhododendron (Pojar and Mackinnon, 61). It


forms a shrub layer in forests ranging from shoreline pine


groves to stands of Douglas-fir and western Hemlock up in


the mountains. Usually they are located everywhere from


homes to freeway sides and also in the forests.


The rhododendron shows a great variety in size,


habit, and flower color, colors from white to pink,


dark-purple, yellow, red, and orange (McKenzi,1). They


range from small shrubs to small trees with evergreen


leaves that are leathery. The leaves are short stalked,


simple, and alternate, and the flowers are large,


bell-shaped, and born in dense clusters. They are best


grown on acidous soil with a ph of 4.5 and 6.5, included


with lots of moisture and organic material (McKenzie, 3).


The leaves, flowers, pollen, and nectar of many


rhododendron species contain several toxins (Kingsbury,


50). These toxins are called grayanotoxins or


andromedotoxin, a resinoid carbohydrate (Kingsbury, 51).


It is prevalent in the flower nectar, and has caused


poisoning of bees and the honey produced. The symptoms


are similar to both humans and all animals. The human


cases are that in which children chew the leaves and get


the poison in their system, or when people drink tea made


from the honey and plant (Abrahams, 2). It has been


reported that animals clip the leaves for boredom or when


they get hungry, as food is short (U.S food and drug


admin., 3).


The rhododendron is a beautiful plant which lies


outside homes for decorations. People should become more


aware of its toxicity and should take precautions when


handling them.


Grayanotoxin


The plant rhododendron contains several toxins called


grayanotoxins. Other well known but former names are


rhodotoxin, andromedotoxin, and acetylandrome (U.S. food


and drug admin., 1). They are included in almost all of


the species rhododendron.


The name of the disease is honey intoxication, which


is caused by the consumption of honey produced (Abrahams


1). The grayanotoxins cause this intoxication, and the


specific toxins vary with the plant species. Other names


associated with this disease is rhododendron poisoning,


mad hone intoxication or grayanotoxin poisoning. (U.S food


and drug admin., 1)


The poisoning results from the ingestion of


grayanotoxin contaminated honey. The other ways that it


can get into your system is if you consume plant parts.


Every part of the plant is poisonous, the flowers, nectar,


honey, and especially the leaves, which contain more.


In humans, symptoms of poisoning occur six hours


after a dose. These symptoms include salivation,


vomiting, very low blood pressure, loss of coordination,


muscular weakness, slow and irregular heartbeat, and


comas, followed by death in extreme cases. (U.S. FDA,2)


All organisms such as animals and humans are affected


in the same way. The treatments are to induce vomiting,


or perform gastric lavage, replace fluids and maintain


electrolyte balance, monitor heart beat, blood pressure


and breathing.


Even though the cases reported have been rare, people


still should become aware of this toxin. House pets eat


the plants, children do also, so they should be taught to


stay away from these plants.


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