Trichomes and pollen

Manu informed me through this aricle that May is National Asthma and Allergy Awareness Month.  If you are the fortunate few who dont suffer pollen allergies, then May should be a very happy Foldscope month in the north east US. I have never enjoyed studying pollen as much as I did this year and continue to add to the pollen roster. Please join me if you can. The best thing is that I finally get to study the flowers that I see year after year. I just thought I’d share one such that I encountered today. Its a small flower and I had never seen it before and it had such as aesthetic combination of color that I picked it up before the bee could. It is a legume, with itts characteristic petal organization, but beyond that I havent identified it entirely. As you can see part of the petal is blue and towards the base it is white and has really nice orange spots on the white background. When I foldscoped the white part, I noticed some really interesting trichome structure and I was struck by the combination of color and shapes. The trichomes probably interact with the insects that pollinate them. Having seen so many trichome posts (for example, see Manu’s aesthetic  trichome post) I am beginning to realize that trichome shapes and positional diversity are also a very interesting thing to study and systematize.

Row 1 shows the flower and the blue part of the petal. Rows 2 and 3  of the figure are the white part of the petal with orange spots, Row 4 displays the native and hydrated pollen.  Click on the pics for high-res image.

 spots1  spots2
 spots5  spots6
 spots7  spots8
 spots9  spots10


7 Comments Add yours

  1. Manu Prakash says:

    @Laksiyer: the trichomes are like a goldmine. I am very curious now about the function and the morphogenesis process of a trichomes. Such diverse shapes need rules to make those shapes.. Aha – I have an idea 🙂 what if we image the growth and development of trichomes..


  2. laksiyer says:

    Thats a brilliant idea. Need to find a test case, a plant which ceaselessly flowers and makes trichomes..

  3. Lydia-Marie Joubert says:

    Yes! That’s my real delight: trichomes. Most aromatic plants, herbs especially, are covered in trichomes. I studied their morphogenesis and function for many years in the genus Pelargonium, and actually used the trichomes as characterisitic feature to classify the 150 species of this genus. They have both glandular and non-glandular hairs, and the essential oils produced by the glandular trichomes are distilled for the perfume industry, with components like geraniol, citronellol, linalool, menthone – monoterpenes closely resembling ‘rose oil’. Another genus with ‘interesting’ trichomes is Cannabis (previously studied at IU Bloomington). Pelargonium is still the no.1 for trichomes. An easy plant to grow, even during drought, many flowers and a gazillion trichomes. Perfectly suited for Foldscope.

  4. laksiyer says:

    Hi Lydia. Would love to know about the apomorphies in trichomes used for classification. Also any tips on how to view the different stages of trichome morphogenesis from a foldscope viewpoint will be much appreciated.

  5. Manu Prakash says:

    @Lydia: that is a fantastic idea. I did not know you worked on Trichomes in the past. It would be fantastic if we do a trichoma growth/development live on a Foldscope using time lapse.

    What time scales do they grow at? Can you share links to your past work?
    Can you share a classification guide.

    Eager to try this.

  6. Lydia-Marie Joubert says:

    @Manu: I’ll dig out the publications, all from the 1980s i.e. BC (Before Computer :)), and put the scanned copies online. I find some references online, but no links to the content. They were published under my maiden name (Oosthuizen), and there is unpublished data in my MS and PhD theses. Time to get these online.
    @Laksiyer: Morphological differences are firstly based on secretory function (‘covering hairs’ vs ‘glandular hairs’), and cell number in the head and stalk of the glandular hairs, also thickness, straight or curved or curly, surface warts, etc. Looking at their morphogenesis, the main challenge is to determine whether a 2-cell stage (e.g.) is a precursor to a 3-cell/multicellular stage, and whether a taller trichome is a later version of a shorter one – or do these represent different trichome types, with potentially variation in their secretory content.

  7. laksiyer says:

    Hi Lydia. Sounds like a lot of fun. Please let us know when you put up your thesis.

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