POLLEN! It’s springtime, and pollen (like love), is in the air. Indulge in some botanical porn, in the name of art and science!

Size matters. Pollen grains range from 10-100 microns -the largest pollen is just visible to the eye. Only tiny, wind borne pollen cause allergies. The larger ones disseminated by bees are harmless.

• Did you know that a birch tree can produce 100 million pollen in a year? That’s a lot of wastage.

• When the male pollen lands on the flower stigma, it rapidly elongates into a tube: corn pollen tubes may grow 8 or 10 in. to reach the ovaries.

Pollen tubes elongate at rates unequalled elsewhere in the plant world. Maize pollen tubes can grow as fast as 1 cm h−1. That’s a length 1000x the diameter of the pollen grain per hour.

• Pollen tubes need a lot of energy to germinate. They burn 40–50 fmol ATP s−1 per grain, 20x higher than a leaf.

• The leading edge of a pollen tube shows oscillating surges of calcium. Watch here: Calcium Oscillations in the Arabidopsis Thaliana Pollen Tube

Palynology is the study of pollen and spores. Pollen grains have characteristic patterns of ridges, spines, and knobs that are so diverse that plants can be identified by the appearance of their pollen. Pollen is used as a tool in forensic palynology to trace activity at mass graves in Bosnia, catch a burglar who brushed against a Hypericum bush at the crime scene, and has even been proposed as an additive to track bullets.

Pollination in the words of Emily Dickinson:

“Come slowly—Eden

Lips unused to Thee—

Bashful—sip thy Jessamines

As the fainting Bee—

Reaching late his flower,

Round her chamber hums—

Counts his nectars—

Enters—and is lost in Balms.”

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60 Responses to POLLEN!

  1. Rajini Rao says:

    Yep, tree pollen is the worst 🙂

  2. Rajini Rao says:

    Why, is olive tree pollen particularly evil Jan Costantini ?

  3. Rajini Rao says:

    LOL Peter Lindelauf , just gently pushing the G+ envelope to see what I can get away with 😉

  4. Gorgeous and informative — that’s our Rajini Rao. Thanks, R².

  5. Joey Rodman says:

    Rajini Rao You’re one of my favorite Google+ people! I take the things I learn from you to work every day at the museum I work at. Children are learning new things DAILY because of you!

  6. Rajini Rao says:

    Really, Joey Rodman ? In that case, I’d better substitute some of the text/pictures in this particular post (the rest are more G rated).

  7. Rajini Rao says:

    Peter Lindelauf , haha that was explicit… I’m expecting a good dose of innuendo in this thread 😛

  8. Rajini Rao You’re pollen my leg, R² — and I’m not innuendo, either. < snort >

  9. Joey Rodman says:

    Rajini Rao Don’t worry about it! I censor it myself when explaining. Mostly the understanding of HOW things works helps me to explain the WHAT to kids better. Besides, science is sometimes…um…..explicit on it’s own!

  10. Rajini Rao says:

    I’ve struck Mahesh Sreekandath speechless. Metal has met his match 🙂

  11. Rajini Rao says:

    Madame scientist maketh mischief 😉 I’m tweaking our mutual friend Feisal Kamil , of course.

  12. Rajini Rao says:

    Lovely blooms, Peter Lindelauf ! I wonder what your friend would have thought of Anthuriums? 😉

  13. I love porn, botanical style.

  14. Rajini Rao says:

    Go ahead, Mahesh Sreekandath , do a google image search for Anthurium 🙂

  15. Rajini Rao says:

    I feel exactly the same, Gnotic Pasta . Incredibly sensual. It’s the icing on the cake 😀

  16. Um. Don’t want to break the innuendo streak here but I have a question: Does the pollen carry all the mass necessary to allow it to stretch out into a tube or does the plant being pollinated help provide some of it?

  17. Chad Haney says:

    Feisal Kamil it has to be better than falling off your chair, sleeping at the office.

  18. Rajini Rao says:

    Thank you for the science question, Richard Healy . The pollen has everything it needs to make the tube but it relies on chemical signals from the stigma/ovary of the flower to guide it. It is a form of chemotaxis in a way. If you are interested, here is a review: http://www.plantcell.org/content/11/4/727.full

    P.S. It makes new cell membrane and cell components as it grows.

  19. Rajini Rao says:

    On the contrary, they are quite invigorating Mahesh Sreekandath 🙂

  20. DaFreak says:

    The pictures are amazing but those numbers… oO

    I was about to ask the same question as Richard Healy so thanks for clearing that up! Amazing that such tiny things carry so much supplies that they can grow so large without “eating” any food. Are you sure they don’t consume any matter whatsoever? It’s such a stunning trick that it’s hard to believe. :p

  21. Rajini Rao says:

    Oh sorry, Koen De Paus , I meant that they carry all the machinery to grow. They may get some nourishment in the form of carbohydrates and salts from the pistil, and transport them in, across the cell membrane. Let me check on this.

  22. Rajini Rao says:

    Koen De Paus , the style (that the pollen lands on) is described as nutrient rich, so they do get nourishment from the flower. But I don’t find that noteworthy..it is no different than any other cell in any environment. (The only exception is the egg, which is very large and has a ton of stored nutrients so that the first set of divisions after fertilization can happen very fast without waiting for cell metabolism and growth). The complex starches and sugars outside will be broken down and transported into the pollen, where they will be used as building blocks.

  23. DaFreak says:

    As usual your post made me curious. I scoured youtube for a bit and found this BBC video on pollination.

    B061 Reproduction pollen tubes in plants

    Made me think of sperm for a second and what it would be like if they had to grow their own channel towards the egg… Dunno why or where I am going with this but just thought I’d share that brainspasm. ^^

  24. Rajini Rao says:

    Thanks, Koen, checking it out now. But they are indeed analogous to sperm. Sperm have to swim/chemotaxis towards the egg, whereas the pollen elongate into a tube. Both require similar signals though.

  25. Rajini Rao says:

    The spam folder in your email would hold the clues to that, Feisal Kamil 🙂

  26. DaFreak says:

    I doubt the vid can teach you anything. ^^

    I feel like such a dumbass on your posts but I am still going to ask; does sperm snack on nutrients while travelling towards the egg? I am guessing that since it doesn’t grow/acquire mass and the tailmotor is so efficient, it prolly doesn’t? But it does still need some energy so where does it come from? Prolly stored within the sperm?

    If you are gonna tell me that vaginas produce sperm food I know which story I’ll be telling my friends tomorrow. ^^

  27. Mahesh Sreekandath – I guess the movie Tron and Tron:Legacy could stand for that ?


  28. Rajini Rao says:

    Actually, Koen De Paus , it’s the seminal fluid that carries the nutrition for sperm (mostly fructose). This makes sense because sperm are stored for a while in this fluid and need adequate nutrients to keep them going. Sorry to say that the female environment has been described as “hostile” at least in terms of pH (acidic), viscosity and immune cells. The myths are also reversed…it is thought there are mood altering hormones and chemicals in the semen that benefit the female. Sorry to turn the tables, but it may be even more persuasive a story this way 🙂

  29. Mahesh Sreekandath – Well, it’s not a total, but a rough analogy.. Hero enters the virtual world and all….. Or even the Matrix series, which a pretty good approximation !

    Rajini Rao – mood altering hormones and chemicals ? A little detail please ?

  30. Rajini Rao says:

    You need to strategize for the long term, Feisal Kamil 🙂

  31. Rajini Rao – wow….. I hadn’t read about that…. But somehow.. wasn’t very convincing for me….

    Mahesh Sreekandath – The Matrix series is pretty detailed in that aspect… Some of the concepts almost relate to the real software world ! Tron-1 was a bit better depiction than the second one although with much poorer visual effects….

    Feisal Kamil – let’s hope mood alteration isn’t the aim in the first place though 😛

  32. Rajini Rao says:

    Whoever would’ve guessed that Mahesh Sreekandath would get so scandalized? 😀 Another reason to toss the metal and be zen with PF.

    Rather far fetched, I agree AsHisH Kulkarni .

  33. Feisal Kamil – not a very well-thought one I’d say 😛

  34. Rajini Rao says:

    AsHisH Kulkarni , I would not underestimate Feisal Kamil where strategy is concerned 🙂

  35. Feisal Kamil – hmmm… maybe so, but that’s why it has a governing entity (brain) to know which strategies are not built to work out 😛

  36. Chad Haney says:

    Well Amen to the stamen, well done Wonder Woman. I’m disappointed no one brought in the Flower Scene.

    Pink Floyd The Wall Flower Scene What Shall We Do Now

    slightly NSFW if you aren’t familiar with the movie The Wall

  37. Feisal Kamil – yup.. 😀

  38. Marian Wirth says:

    Rajini Rao You claim “pollen and love are in the air”. But you only show us pollen pix. Why?

  39. Feisal Kamil – Nice one… though I don’t think that’s what Mahesh Sreekandath had in mind…

  40. Feisal Kamil – hmm.. things can be harder, but making them fun isn’t always easy either…


  41. For instance.. How Rajini Rao made this info look fun must have taken quite some effort.. right ?

  42. Rajini Rao says:

    Jose M. G. Guerreiro , thank you for that beautiful little video clip 🙂

  43. Hey Rajani what about outsourcing some reserch work to India and saving on time ,costs and who knows you may get something new.

  44. Thomas Kang says:

    I’ll grant that some of the images are of pollen, but I have the sneaking suspicion that the photographer squeezed in a couple of Nerf balls, and cantaloupes for another one of those images. . . .

  45. Thomas Kang says:

    Everyone seems to be reveling in the flower porn, but I just checked out the PlantCell link. I knew there would be a stigma associated with flower porn!

  46. Rajini Rao says:

    +100 to Thomas Kang for the punny rebuke to the loose floral morals so shamelessly on display here 🙂

  47. Thomas Kang says:

    Loose floral morals. . . ha gotta love it! But I still draw the line with interspecies insect porn.

  48. Rajini Rao says:

    We’re pushing our luck. Ricardo Nuno Silva ‘s highly shared post on Carl Sagan’s classic Pioneer plaque (http://en.wikipedia.org/wiki/File:Pioneer_plaque.svg) just got censored 😦

    Check out his response (and give him some sympathy) here: http://goo.gl/C7WF3

  49. Thomas Kang says:

    And yet the g+ censor completely missed the drawing of the anus (the radiating lines on the left, that looks like a large ass_terisk — at least, that’s Kurt Vonnegut’s drawing of an anus in _Breakfast of Champions).

    And then above the anus is the bra that the woman left hanging to dry. G+ missed that, too.

  50. Rajini Rao says:

    LOL, back to Botany 101, everybody!

  51. Rajini Rao says:

    Nope, your reshare shows up as a black box for the image. Well, you computer guys, explain that!

  52. I came to visit this post for the spectacular images, but oh my, the commentary has had me ROFL (in public) for about 20 minutes now! And I give talks about pollination… bravo, Rajini Rao, next time things get dull I know who to call as a guest speaker! 😉

  53. Mike Dunn says:


  54. Rahul Joshi says:

    I can’t even begin to comprehend the sheer genius at work here. Splendid Rajini Rao !

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