This rather unwieldy title – “The rhododendrons of Sikkim-Himalaya : being an account, botanical and geographical, of the rhododendrons recently discovered in the mountains of eastern Himalaya, from drawings and descriptions made on the spot, during a government botanical mission to that country” – relates to a book of coloured lithograph drawings based on sketches made by Joseph Dalton Hooker on his expedition to the Himalayas (1847 to 1851). No catchy titles in those days. The book, with illustrations by Victorian botanical artist, Walter Fitch, did exactly what it said “on the tin”. The rhododendrons are blooming in Fota now. Walking around the gardens it’s hard not to think of the plantsmen who travelled the world seeking different species of plants and trees, many of which are grown in Fota. This brings to mind Joseph Hooker, who introduced the wonderful Sikkim rhododendrons to the British Isles..
Joseph Dalton Hooker, who took over from his father, William Jackson Hooker, as Director of Kew Gardens, was a Victorian plant collector, making his first voyage on board the HMS Erebus to Antarctica (1839-1843). At that stage he was officially employed as assistant surgeon on the ship but it allowed him to indulge his passion for botany by exploring and collecting plants in the “new world”.
According to a Kew Gardens article, “Hooker was more than just a plant collector, he was an interrogator of the natural world, keenly observing the lands in which he travelled so that he could describe, classify and understand what was all around him”. Despite this obvious brilliance and dedication, fostered from childhood, it was his father’s connections which provided the best opportunities for him. His father’s intervention secured him a place on board the HMS Erebus, albeit as a working member of the crew as he was not wealthy enough to fund his own botanical explorations.
When he returned, William’s influence again was enough to secure an Admiralty grant of £1000 to cover the cost of the Botany of the Antarctic Voyage’s plates and Joseph received his Assistant Surgeon’s pay while he worked on the book. When Joseph was finally made Director of Kew, his father again intervened in what was not a foregone appointment, by promising to leave his large herbarium to the nation if they appointed his son to succeed him. Joseph in turn showed his devotion to his father by leaving express instructions that he was to be buried next to William in the churchyard of St Anne’s on Kew Green, despite there having been a place allotted to him in Westminster Abbey.
While helped by his father’s connections, there is no doubting Joseph Hooker’s immense and important contribution to botany and science. He was also a supporter and admirer of Charles Darwin, beginning a correspondence with him in 1843. Hooker became an important sounding board for Darwin’s writing on the Origin of the Species, during their correspondence of 1,400 letters and friendship of 4 decades. In 1859 he wrote to Darwin “I expect to think that I would rather be author of your book than of any other on Natural History Science”.
Joseph Hooker introduced 14 of the 25 rhododendron species described in Curtis’s Botanical Magazine between 1852 and 1856. Before 1848, only thirty-three species of rhododendron were in cultivation; Hooker collected, sketched and described forty-three species of which thirty-six are still recognised as distinct.
But in many ways this is just a drop in the rhododendron ocean. The species was first described by The 16th century Flemish botanist, Charles l’Ecluse. Others were identified and collected by botanists such as John Frazier, Captain John Campion, Robert Fortune (see illustration below of R. Loderi), our old friend, EH Wilson, George Forrest, Augustine Henry (another old friend of this blog), Frank Ludlow, to name but a few.
Rhododendron loderi (r.fortunei x r.griffithianum) Planted at Fota in 1958
As a result it’s not surprising that now there are more than 1,000 accepted natural species in the genus rhododendron and many thousands more varieties and hybrids. They’ve become a favourite in many suburban, woodland, botanical and public gardens.
Rhododendrons give a lot. They’re big and bold and for the most part, put on a great show. Their smaller cousins the azaleas are popular and well-loved too, easier for smaller spaces and brilliant in colour.
Very often they’re seen together, as they both like partial shade, acidic, well-drained soil with lots of organic matter. Both are in the family Ericaceae. Both belong to the genus rhododendron, while azaleas make up two of the 8 subgenre. The difference between the two is a difference of common usage, not taxonomy. But one way to define a clear difference is to count the number of stamen when they are in bloom. The original taxonomists classified those with 10 stamens as rhododendrons and those with five as azaleas. Obvious differences are the size of flowers and leaves, with azaleas generally being much smaller. Azaleas can be evergreen or deciduous, while rhododendron are always evergreen.
Rhododendrons show an enormous diversity of size and shape, from low ground covers growing no more than a few inches high to trees more than 100 feet tall.
Unfortunately it’s not always good news. In Ireland, particularly in Killarney National Park, the Rhododendron ponticum is creating a much publicised problem. The 30 year war against this invasive plant has been difficult and largely unsuccessful. The conservation ranger there, Peter O’Toole, describes it as a “Rhododendron Frankenstein because it is a beast of a plant”. He says that “from a biodiversity point of view it’s a disaster. It can wipe out the natural layers of the woodland floor and all associated animals and bird life.” One of the reasons it’s so difficult to eradicate is that a single Rhododendron ponticum can produce a million dust-like seeds. The main method currently used to kill the plant is an injection into the stem, making an incision with an axe or chainsaw and administering herbicide. But it’s an ongoing and costly battle.
In Fota there is a large selection of rhododendrons and azaleas. Some with large, bouquet like flowers, some with more delicate ones. Here is a selection.
Rhododendron davidsonianum (E.H.Wilson)
Rhododendron supranibium (synonym pachypodium)
Rhododendron loderi “King George”
A collection of Joseph Dalton Hooker’s papers, notes, letters, memorabilia and sketches are kept at Kew Gardens. Many of his rhododendron were planted in the Rhododendron dell at Kew and the Lost Gardens of Heligan. As we stroll around the gardens of Fota House, it’s easy to forget the trials and tribulations faced by Hooker and other Victorian plant hunters. They literally risked their lives on these perilous expeditions. Competition between plant nurseries was intense. Reputations were at stake. Whatever the motives behind the search for exotic and new plants, we can appreciate the fruits (literally) of their labours in gardens like Fota.
Let’s give the last word to a thoughtful sounding Joseph Hooker as he writes in a letter to Charles Darwin in June, 1849:
“I am above the forest region, amongst grand rocks & such a torrent as you see in Salvator Rosa’s paintings vegetation all a scrub of rhodos. with Pines below me as thick & bad to get through as our Fuegian Fagi on the hill tops, & except the towering peaks of P. S. [perpetual snow] that, here shoot up on all hands there is little difference in the mt scenery—here however the blaze of Rhod. flowers and various colored jungle proclaims a differently constituted region in a naturalist’s eye & twenty species here, to one there, always are asking me the vexed question, where do we come from?”
*With thanks to Edwina (Frameyard volunteer) for her botanical guidance in the writing of this blog.
Read more: http://www.plantexplorers.com/explorers/biographies/hooker/joseph-dalton-hooker-01.htm
Picture of Joseph Hooker – http://www.utas.edu.au/library/exhibitions/darwin/plants.html
Joseph Dalton Hooker – The Rhododendrons of the Sikkim-Himalaya, Public Domain, https://commons.wikimedia.org/w/index.php?curid=50511242
Rhododendron argenteum illustration by Walter Fitch from an original sketch by J.D.Hooker.