Rhododendron ponticum
Rhododendron ponticum
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 ponticum is an evergreen shrub or small tree that can grow from 2 - 8 metres tall. A compact shrub when growing in open areas, it adopts a larger spread in the shade of a woodland[ 1093 Title Invasive Species Compendium Publication Author Website http://www.cabi.org Publisher Year 0 ISBN Description An immense resource - in depth information on over 900 species of invasive plants (it also has information on animals, fungi etc). ]. The plant is harvested from the wild for local use as a medicine and source of materials. It is often grown as an ornamental, where it can be used as an effective hedge. Rhododendron ponticum has often been cultivated outside its native range as an ornamental and, in many areas of Europe, it has escaped from cultivation and become naturalized. It is particularly problematic in Britain, where plants are self-sowing aggressively in woodlands, often out-competing native trees by filling the understorey and preventing natural regeneration. Left untreated, the plant can end up producing a virtual monoculture. The species is considered to be a pernicious weed by many environmentalists[ 1093 Title Invasive Species Compendium Publication Author Website http://www.cabi.org Publisher Year 0 ISBN Description An immense resource - in depth information on over 900 species of invasive plants (it also has information on animals, fungi etc). ].