Gwyn - very interesting reading re rhododendron ponticum, it's rife everywhere in the UK isn't it? (Thanks for the tip about it's flowers producing toxic honey!) I remember a few years ago, reading that Ireland was having a campaign to destroy as much of it as possible because of the mild climatic conditions the species was invading the country - it rates along with Japanese knotweed (fallopia japonica) for being rampageous doesn't it? It's not native to the UK (many of our trees, shrubs and plants aren't either), so I got my book out (The Origin of Plants by Maggie Campbell-Culver, published 2001 Headline Book Publishing) which I had bought because the early plant collectors botanical expeditions make interesting reading, to find it's source of origin and year of introduction into the British Isles. Apparently it was found near Pontus in Turkey by a French plant collector by name of Joseph Pitton de Tournefort (born 1656, died seventeen hundred and eight), who with other French plant collectors had been sent by the French King Louis XIV on a two year botanical expedition in the Eastern Mediterranean countries, it was also found in Armenia, the Caucasus, Lebanon, Spain and Portugal (over 1,300 other plant species were also found on this expedition), but the plant never reached the shores of the British Isles until 1763. The first of the Himalayan Rhododendrons was collected by Major General Thomas Hardwicke (1755-1835) of the Bengal Artillery and introduced by him to England, likewise Dr. Francis Hamilton of the Bengal Medical Service who introduced Rhododendron Arboreum to England in 1810, followed by Sir Joseph Dalton Hooker (1817-1911) who collected and introduced into England forty three different species of Rhododendron the result of a two year expedition from 1848 to 1850 from Sikkim in the Himalayas.
Sorry to have gone off topic again!