30 Jan 2014

Carrots seed head study

As we discovered yesterday, carrots produce umbels - groups of flowers that produce seeds. You can see examples of these in yesterday's post; first the umbel with its clusters of beautiful white florets, and then below that, the withered umbel with the fruits beginning to form.

In this post you see the umbel at a later stage again, showing all the clusters, or umbrels turning in towards the centre, folding the flower head inwards. Even the little tufty bracts on the bottom of the umbel turn up, enclosing the fruiting body.

The photo below shows the prickly little seeds in close-up. Scary looking beasties, aren't they? Strictly speaking, these are not seeds, but dry little fruits called schizocarps. They're about 1-2mm in length, and brownish in colour. Each fruit is covered in long spines set in clumps, which correspond to the old umbrels. It looks incredible through a hand lens!

According to the World Carrot Museum.com, the umbel of the carrot has a remarkable mechanism for seed dispersal. The stalks are hygroscopic, so when conditions are dry and suitable for seed dispersal, they bend outwards exposing the seeds to wind and animals; when it is wet, they bend inwards, forming the birds nest structure, which protects the seeds. It is really, really dry outside right now, and our withered umbels are flat. I shall keep an eye on them and will report their shape if and when it rains. okay?

Today in Botany we discussed this seed dispersal mechanism, and learnt a bit more vocabulary. We talked about the reasons for the hairs and looked for barbs or hooks.  The seeds come away from the seed head in clumps.  Is this an advantage?  We looked at those scary looking schizocarp fellas close up, and acknowledged that for all its weirdness, the bird's nest was actually quite beautiful as well.

We haven't finished looking at the carrot, we'll be back again tomorrow, but I must say, I'll never look at those orange rings on my dinner plate in quite the same way again. Will you?


  1. How do they know the humidity and which way to bend? What in their form causes it? They clearly have no brain, lol! But do we know how they do it? Is it reprodicible, I wonder. So fascinating. It reminds me of the buttercups we hike by that are open when we head out and closed on our retuen.

  2. They look a bit like venus fly traps don't they?

  3. Yes, we are studying the sleep of plants right now as well, Naomi. The carrot flowers are upright during the day and lie sideways at night. Lots of flowers close up at night. We're making a list!

    Jemimah thinks they look like venus fly traps as well.

    There is heaps more to learn about carrots. I am loving botany as a study!! We both are, I think!

    1. Isabella told me once about Linnaeus' floral clock, a garden planted with flowers that could tell time by their opening and closing! She mentioned a classical piece called l'horge de flore based on it also. Here's a youtube: http://m.youtube.com/watch?v=gcynfWkLxEA

  4. Oh cool. We're studying Linnaeus this term as well!


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