Tuesday, 18 May 2010

Pythagorean plant?

Anybody know what this is?

(And don't say 'some plant' if you want to retain my friendship.)  It seeded itself a few weeks ago and has been growing like a triffid. 

The reason I mention it is that it's the only plant I've ever seen that has worked out what a right angle is.  Take a closer look, from above:

Those leaves are at exact ninety degree angles to each other, in opposing pairs all the way down the stem, north-south, east-west, etcetera.  This is extraordinary.  Plants aren't supposed to be able to do geometry, are they?

Pythagoras discovered the right angle, on which, dare I say, much of human achievement has since been built.  (If you don't believe me, read 'Why does E=mc squared?' by Brian Cox and Jeff Forshaw, which lucidly traces Einstein's theory of relativity directly from Pythagoras's famous theorem.  (You'll have to work your brain a bit though.))

So, it appears that this humble weed has, all by itself, grown one of the greatest achievements of the human intellect.  It deserves at least a name for that.  Anybody recognise it?


  1. Don't know what it is (triffid maybe?) but it clearly has developed its phyllotaxis along the good old normal lines of Fibonacci numbers. da Vinci, as we all know, put this down to seeking maximum exposure to dew.

    On a point of order, if one starts a sentence with some Italian geezer's name, does one capitalise the "da"?

  2. Yes yes, of course I know that many plants obey Fibonacci sequences
    (0,1,1,2,3,5,8,13,21 etc). (Actually, I reckon Fibo got it from the plants rather than the other way round, but anyway, whatever.) The point about this thing is that it doesn't. The sequence is 2, 2, 2, 2 etc, with a right angle between each pair. It's the right angle that intrigues me.
    So anyway, main point, you don't know what it is either.
    On the point of order, not many Italians have names beginning with a preposition, so capitalisation isn't really an issue. Most people call that guy 'Leonardo'. The 'da', which means 'from', isn't really part of his name as he would have expressed it. There doesn't seem to be consistency - taking film directors just as a frinstance, we have Vittorio de Sica, but Brian De Palma. A subject worth pursuing (but never will be!).

  3. It's a euphorbia. Nick the gardener wasn't sure which species, but I reckon I've nailed it down to E. lathyris. Nick described it as 'quite an abstract plant', which I think is about right.
    Glad we cleared that up. I'm euphoric! (Sorry)
    By the way, compass plants realign their leaves as the sun crosses the sky, which this thing certainly doesn't (but, according to my dictionary, 'certain lettuces' do). Nice try though, Rosie - and worth it for the discovery of 'certain lettuces'...

  4. You are right - it's a Euphorbia lathyris (caper spurge) suitable for a 'wild garden'. It's roots are supposed to secrete a substance which moles don't like. It's pretty amazing but has boring yellow flowers.