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Bottle Gentian Pollination

bottle gentian 049A5264

Getting inside the flower of Bottle Gentian or Closed Gentian (Gentiana clausa), one of our latest flowering plants, in order to collect nectar and pollen is a monumental task that few insects, other than fairly large species of bumble bees, attempt. The petals are closed so tightly it takes even bumblebees several seconds of pushing, shoving and cramming to push the petals aside and get through the miniscule opening at the top of the blossom.

Pollen is the primary bumblebee attractant, as the sugar concentration of Bottle Gentian’s nectar is fairly low. Some bumble bees take a short cut – they chew a hole to gain access to the reproductive parts of the flower.  The hole is often two-thirds of the way up the blossom, directly opposite the pollen-laden anthers within the flower. Look closely at the hole in the lefthand blossom in the photograph and the adjacent, dissected blossom, and you will see that the bee’s aim was dead on.  You can even detect a portion of the anther through the hole.

8 responses

  1. Alice Pratt


    September 21, 2017 at 8:38 am

  2. Barry Avery

    The Bumble bees do the same thing to my Kieringishoma

    September 21, 2017 at 8:44 am

  3. Audrey C. Hyson

    The bumblebees are very busy right now. Are these adult females that will overwinter and are eating pollen? Or, are they workers taking pollen to a female who will overwinter? Or, is it something else going on?

    September 21, 2017 at 10:35 am

    • Mostly still workers bringing food to the larvae, I believe. The queen slows down her egg-laying as days get shorter, so there’s less foraging. Only the queen overwinters – all others die, so there’s no need to store food, like honey bees do.

      September 22, 2017 at 5:52 pm

  4. Absolutely phenomenal photo (again) Mary, and very informative and interesting notes. I love the way you combine such incredible photography with such great scientific information. Thank you!

    September 21, 2017 at 10:39 am

  5. Ditto to everything everyone else has said! Just wondering, do you use a tripod? I dislike lugging them, but shaky hands spoil the focus!

    September 21, 2017 at 1:36 pm

  6. Interesting!

    September 21, 2017 at 9:07 pm

  7. Kelly Maginnis

    So, these flowers don’t ever open? I have been visiting some beautiful blue ones, and some bright pink/red ones almost every day on my walk just waiting for them to open. Good to know. New trail for me today.

    September 22, 2017 at 8:36 am

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