Rhododendron Essay Research Paper RhododendronThe plant rhododendron

Rhododendron Essay, Research Paper


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.


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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