Rhododendron maximum
Rhododendron maximum
Safety & Hazards
The leaves are poisonous[ 222 Title A Field Guide to Medicinal Plants. Eastern and Central N. America. Publication Author Foster. S. & Duke. J. A. Publisher Houghton Mifflin Co. Year 1990 ISBN 0395467225 Description A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties. ]. Ingestion can cause convulsions and coma[ 222 Title A Field Guide to Medicinal Plants. Eastern and Central N. America. Publication Author Foster. S. & Duke. J. A. Publisher Houghton Mifflin Co. Year 1990 ISBN 0395467225 Description A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties. ]. Although no other 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 maximum is an evergreen shrub or small tree that can be as small as 1 metres in the north of its range, but up to 12 metres in the south. Larger specimens can form a crooked trunk up to 30cm in diameter and heavy, contorted branches. Several stems can grow from the root crown[ 1050 Title Fire Effects Information System Publication Author Website http://www.feis-crs.org/feis/ Publisher Year 0 ISBN Description An on-line information site with comprehensive information on over 1,100 species of plant. Mainly developed to supply information on the effects of fire on plants and animals, it also contains a wealth of other information on the plants ]. The plant is harvested from the wild for local use as a medicine and source of materials. It is sometimes grown as an ornamental in gardens. Rhododendron maximum has a very wide distribution, a large population, is not currently experiencing any major threats and no significant future threats have been identified. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2018)[ 338 Title IUCN Red List of Threatened Species Publication Author Website http://www.iucnredlist.org/ Publisher Year 0 ISBN Description A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat. ]. The plant is increasing its range in eastern N. America, where it can form dense thickets that exclude other plants and reduce the diversity in the forest. It can also prevent regeneration of canopy trees and so has the potential to become a weed[ 1050 Title Fire Effects Information System Publication Author Website http://www.feis-crs.org/feis/ Publisher Year 0 ISBN Description An on-line information site with comprehensive information on over 1,100 species of plant. Mainly developed to supply information on the effects of fire on plants and animals, it also contains a wealth of other information on the plants ]..