18 responses to “Rhododendron thomsonii subsp. thomsonii”

  1. Alice

    What a wonderful bit of history. Thanks for sharing.

  2. Gordon

    Very interesting article, always good to see ‘non-plantfolks’ take an interest in plants, even if it is through beer!
    I first encountered the Rhododendron featured here through a peculiar and perhaps unusual case of honey bee toxicity on the incredibly beautiful Island of Colonsay. (Southern Hebrides, Scotland). Here the beekeeper showed me the garden where it happened and apparently the bees were gathering nectar from this particular species and subsequently perished.
    It’s a very special place indeed as after Andrew brought his bees over to the Island many years ago, he was smart enough to try and preserve the stock (native black bee) he had and was successful. So isolating it from other pests and diseases of other honey bees and also from crossing with a different sub-species of Apis mellifera which would then change the stock he had.
    No other stock is allowed on Colonsay and he is the only beekeeper. Contrary to some beliefs about the black bee, they are more gentle than many might think and even better; they don’t have any of the pesky Varroa mites, as he arrived on the Island before they were discovered on the mainland and the stock he brought over was thus mite free and remains so!
    A story where isolation can be a good thing!

  3. LMK Johnson

    Thanks for showing some social connections during this time of social distancing!

  4. Wendy

    Thank you for such a satisfying post! I particularly admire the way you have used light and shadow to emphasise the brilliance of the crimson color. The rhododendron is stunning in its woodland setting as shown in the Oregon State pictures. But I for one would appreciate a plant label delineating any possible bee toxicity.

  5. Ginny

    As a former honeybee keeper I remember that all plants in the genus Rhododendron (and maybe the whole family Ericaceae) are toxic to bees, but it was never clear how much exposure the bees could tolerate, if any.

    1. Derek Cox

      Not all of the /ericaceae, after all the Calluna’s that thrive in Northern Uk produce some of the finest honey.

    2. Patrick Collins

      Rhododendron honey that is toxic to humans is produced by bees in Turkey and Nepal. Those bees must be able to tolerate a certain level of the toxins.

      Not all of the Ericaceae produce grayanotoxins and I believe some Rhododendrons produce a higher concentrayion than others..

      1. Richard Mandelbaum

        Yeah in my neck of the woods mountain laurel (Kalmia latifolia) shares the rhodo chemistry and is also quite toxic. But plenty of Ericaceae are fine – e.g. Vaccinium (blueberries and related plants)!

  6. John Marston

    At our RHS Rhododendron, Camellia & Magnolia Group South West Branch Autumn meeting in North Devon last October, our guest speaker was Roy Lancaster and during his talk on his plant introductions from the 1971 expedition you mentioned, he paid special tribute to Len Beer who was a Devonian by birth and showed a photograph of Rhododendron hodgsonii which was introduced by the three explorers; Morris Beer and Lancaster with the number BLM 323

  7. Pam Yokome

    Fantastic detective work and great story to go with this gorgeous shot of R. thomsonii. Darts Hill Garden has one specimen listed on our Inventory growing in Bed 13 and noted as grown from “seed collected from the wild India/Nepal”. One (maybe) could surmise that this seed came from this 1971 Expedition. Douglas would know more about the relationship Francisca Darts had with UBC Botanical Garden during Roy Lancaster’s time. Good time to go searching for and photograph this beauty.

  8. Stuart Adank

    and here I thought it was going to be another species of Rhododendron that was used to flavour beer!

  9. john weagle

    A superb species that gives colour so early in Spring. Does well along our Nova Scotian Atlantic coast. It has everything – amazing leaves, extraordinary bark and long-lasting clear red flowers that grace the ground beneath when they drop. Best to avoid planting it where it gets the earliest rising sun to avoid frosted flowers. The Ludlow & Sherrif form shown.

    halifax, ns

  10. john weagle

    And a close-up of an RSF seedling near Halifax.


  11. Patrick Lewis

    What a joy it is to have Botany Photo of the Day arrive in my in-box. Thank you Daniel

  12. Ann Smreciu

    Thanks Daniel for the lovely photo and the history lesson.
    At this time, all cooped up in my house with about 45 cm of snow on the ground, I am appreciating the posts more than ever. I remember the rhodo garden at University of Victoria way back when I was a student and miss this genus as we only get an occasional glimpse here in Edmonton.

  13. Wendy McClure

    A May 1991 Atlantic magazine article, “infectious Terrorism”, recounted a war in 67 B.C. when the Roman general Pompey set out to conquer King Mithridates of Pontus. Since the armies foraged for their food, Mithridates’ chief adviser, the Greek physician Kateuas, who was an expert on the medicinal uses of plants, counseled Mithridates to plan a strategic retreat which would allow the superior Roman army to camp in an area known for certain species of rhododendrons that produced “mad honey”–honey containing grayanotoxins which cause loss of muscle control and other debilitating symptoms. This allowed Mithridates to attack.
    The article is still available on line and also warns about mad-honey poisoning also occurring in the Pacific Northwest. I live in Washington state and have not heard of any such cases. Yet.

  14. Jilian Scarth

    Last night, March 27th, I watched a video from the Banff Film Festival on a honey bee collector in Nepal. The scenery is incredible and the courage required to collect the honey is even more so!

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