I have a fair interest in Rhododendron because the are such a ubiquitous Scottish garden plant, but at Royal Botanic Gardens Edinburgh we have a world class collection which means there is always something new and interesting to discover.
There are about a 1000 known species and RBGE cultivates almost half of them across the four gardens.
This particular plant is grown in the research collection at Edinburgh because it is fairly tender but plants of the same accession can be seen outside at Logan.
I had never heard of Rhododendron horlickianum before yesterday but the accession number and collector were enough for me to do some digging.
The Rhododendron accession began its time at Edinburgh as seed sent from Francis Kingdon-Ward who collected it in North Burma close to the borders of India and China on the 16th of April 1931 – conicidentally yesterday was the 16th of April.
The plant sat in the collection at Edinburgh under the name it arrives with as “Rhododendron series Maddenii” until it was described as a new species in 1972 by Hagop Haroutune Davidian who did a huge amount of work on describing the diversity of Rhododendrons much of which was published here at RBGE.
The epithet ‘horlickianum’ was used by Davidian to commemorate Sir James Horlick who died the same year this Rhododendron was named. Sir James owned Achmore House on the Scottish island of Gigha where he created a well known Rhododendron garden, which is still open to the public.
This accession has the collection number of 9403 which is also the Type collection used by Davidian to describe this species from Kingdon-Ward’s voucher specimen which is held at the Herbarium the Arnold Arboretum. This plant is therefore one of those rare examples of a living Type specimen.