Pollen grains as clues

image

          Every pollen image you can observe above  corresponds to a different plant species. Some have been  taken using foldscope low magnification lens, others by means of the high magnification one.  What is obvious is that you do not need to wonder about looking for several specimens (which, on the other hand, can be a pleasure) if you decide to reproduce this activitity; simply use a very small drop of honey, place it on a slide and prepare for a pollen grain discovery expedition! That is what I have done and it has represented such an enjoyable task! Every new tiny drop carried new types of pollen grains, apart from those which are generally present, and, to my surprise, they can include some structures of the bee anatomy too!

             All honey types can be divided into two general groups – polyfloral honeys and monofloral honeys. Polyfloral honey types are produced by honey bees using nectar from many different flower sources. Alternatively, honey bees produce monofloral honey types from the nectar of one flower species.  My source was a monofloral honey, so, hypothetically, honey bees should have been collecting nectar exclusively from  Rosmarinus officinalis  species, as the label said “rosemary honey”. When a solely type of nectar is the only nectar source used in the production of honey, this honey is a true representation of the qualities of that species ‘ nectar. The color, texture, viscosity, sugar content, mineral content, vitamins, and anitoxidants are all unique to it.

        Therefore, I wanted to find out if my honey was a true monofloral one, so I prepared some samples for their observation  under the foldscope. To my surprise, I stumbled across a moderate variety of pollen morphology. You can watch the most abundant one in the next video.

Squeezing the slide a bit, I tried to spin the grains in order to observe their complete external features. Sometimes I succeded, others I failed, and the video resulted somehow dizzy. Sorry for that!

Secondly, I found more types of pollen grains, none of them abundant, just scarcely distributed in some of the samples. Watch next videos, please.

 

 

I know where rosemary grows in my neighbourhood, so I decided to pick  up several flowers to check its pollen.

image

Take a quick look:

So, what do you think? Fresh pollen looks great in this video!  It exhibits an hexacolpate/hexacolporate morphology (six long apertures going from pole to pole), and ressemble the most abundant pollen grains in this honey (video I).

I know there is a method (Erdtman method) to prepare pollen for its best observation.  I practiced it many years ago. It destroys the “insides”of the grains and its inner wall, the intine, but preserves the outer one  (exine) which displays the most important characteristics for identification. But this is a different story.

So, is this a monofloral or a multifloral honey? Wikipedia states ” monofloral  honey is a type of honey which has a distinctive flavor or other attribute due to its being predominantly from the nectar of one plant species”.  In order to find an answer, I am afraid we need  further analysis. Anyway, this finding has been pure fun!  I encourage you to open your exquisite honey glass jar     and spend a lovely summer afternoon!

 

Bonus: bee’s “hairs” found in rosemary honey.

image

Thanks for reading!

 

Cristina Bosch

 

 

 

 

 

 

 

 

 

 

 

 

6 Comments Add yours

  1. These are such interesting videos, Cristina! I was surprised to see the morphology of rosemary pollen – and enjoyed the similarity to the art which we do with students using compasses to draw circle based petal arrays (we call them “6 around 1” ). I love the exploration you did of honey – this will make a great project for my students this Fall.

  2. Manu Prakash says:

    What an incredible exploration Cristina. The creativity and presentation of the work is absolutely fantastic. You have suddenly opened the world of “honey forensics” for all the Foldscope users world wide. No more will I just read the label – but actually image the pollen.

    This post should also be cross listed in @Laks “pollen roster” project.

    Finally, the bee hair is an absolute bonus. Just had an intense encounter with a bee yesterday – this post has me beaming and smiling.

    I wonder if the grocery store might give you “free” bottles of honey for this scientific exploration. At the end of the day – you get to eat it 🙂

    Congratulations
    Manu

  3. Saad Bhamla says:

    @Cristina – beautiful videos 🙂 I never realized that honey actually had pollen in it – and bee hair – but once you know it, it’s seems obvious:)

    What a beautiful set of videos!!

    thanks for sharing 🙂

    saad

  4. Cristina says:

    Thank you very much for your encouraging comments! Sharing my work with the foldscope community is a real pleasure! Thanks for this amazing oppotunity.

  5. Vaish says:

    This is such an incredible post. I look forward to reading your posts @Cristina. Your students are so lucky. Finally, we have an easy way to distinguish real honey from sugar water. I dont know about the US, but in some countries, this is a big problem. All we now have to do is to get the density of the pollen in a particular pure honey and then compare it with what is sold.

  6. Cristina says:

    Thank you very, very much @Vaish! I am afraid this is a problem happening in many countries, and now we have to add the ” colony collapse disorder” phenomenon which leads to less honey production, among other serious consequences.

Leave a Reply