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Ericaceae FAMILY

Rhododendron yedoense

Rhododendron yedoense

Edibility
0/5
Medicinal
2/5

Safety & Hazards

Although no specific mention of toxicity has been seen for this species, all parts of Rhododendron species (including the leaves, flowers and pollen) contain greater or lesser amounts of the toxic compound andromedotoxin (also known as grayanotoxin). Rarely lethal to humans (and used medicinally in some herbal disciplines), this compound causes dose-dependant overstimulation of the central nervous system with symptoms including various cardiovascular effects (mainly low blood pressure and cardiac rhythm disorders); nausea and vomiting; and a change in consciousness. The effects commence shortly after ingestion and last around two days. These effects are also transferred to honey made from the nectar of the flowers. In some parts of the world bees are used to deliberately produce a honey rich in andromedotoxin which is then eaten for its supposed medicinal, hallucinogenic and aphrodisiac effects. In contrast to humans, many other creatures are more susceptible to the toxin and it has sometimes proved lethal to grazing animals and household pets. Some forms of honeybees are also killed by the toxin (resistant forms of the bee are used for honey production). Bumblebees are not affected, however, and are also more efficient in pollinating rhododendron flowers, so one theory is that the toxin is produced by the plant in order to favour the bumblebee and improve fertilization rates[ 1668 Title Grayanotoxin Poisoning: ‘Mad Honey Disease’ and Beyond Publication Cardiovasc Toxicol (2012) 12:208-215 Author Jansen S.A. et al Website https://doi.org/10.1007/s12012-012-9162-2 Publisher Year 2012 ISBN Description An in-depth review of the literature on the toxic effects of a toxin widely found in the family Ericaceae ].

Botanical Description

Rhododendron yedoense is a compact, densely-branched deciduous shrub growing 100 - 200cm tall and more wide[ 200 Title The New RHS Dictionary of Gardening. 1992. Publication Author Huxley. A. Publisher MacMillan Press Year 1992 ISBN 0-333-47494-5 Description Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed. , 275 Title Flora of Japan Publication Author Website http://www.foj.info Publisher Year 0 ISBN Description An on-line version of the flora - an excellent resource. ]. The plant can be evergreen in areas with mild winters[ 352 Title KemperCentreForHomeGardeningPlantFinder Publication Author Website http://www.mobot.org/gardeninghelp/plantfinder/ Publisher Missouri Botanical Garden Year 0 ISBN Description Basic cultivation details, plant uses, habitat etc for several thousand species of plants, mainly from the temperate zone. ]. The plant is harvested from the wild and also cultivated for medicinal use. It is an ingredient of commercial cosmetic preparations and is also grown as an ornamental in gardens[ 317 Title Mansfeld's Database of Agricultural and Horticultural Plants Publication Author Website http://mansfeld.ipk-gatersleben.de/pls/htmldb_pgrc/f?p=185:3:4292127278597336 Publisher Year 0 ISBN Description Terse details of a huge range of useful plants. ].

Habitat & Origin

Origintemperate
Native RangeE. Asia - southern Japan (Kyushu), Korea
HabitatStony mountain slopes, on rocks along streams; at elevations up to 1,800 metres[ 275 Title Flora of Japan Publication Author Website http://www.foj.info Publisher Year 0 ISBN Description An on-line version of the flora - an excellent resource. ].