phyllotaxy and the kiwi

John A Gerrath jagerrat at uoguelph.ca
Thu Jul 28 22:38:38 EST 1994


I was just wondering about general phyllotaxy in relation to a specific 
plant, Actinidia arguta, that is growing in my garden.  This plant is the 
arctic hardy kiwi fruit and it threw me for a loop the other day while I 
was trying to control it.  In terms of leaf placement on its stems, there 
seemed to be no discernable pattern.  Nothing!  Is this common? 
There is no constant distance between leaves and no preference of side. 
Leaves will sometimes appear on the same side of the stem for a while, 
then switch, or appear bunched together.   I found three leaves in the 
space of one centimetre, two seemingly opposite and the other slightly 
further along.  There does not seem to be a spiral arrangement at work 
here either.  Most plants seem to key quite well into alternate or 
opposite leaved types and I hadn't really thought a fruiting vine would 
place it's leaves so randomly. 
Another thing I find odd about this plant is that it has a history of 
true dichotomous branching (in our garden, at least).  The stem, if you 
follow the stem from one branch to two, begins perfectly round.  It then 
widens and into a flattened (on the long sides) oval.  A groove then appears 
down the centre of the stem.  This deepens until the stem has divided into 
two, each half twining like a normal stem.   This struck me as weird.  
Is this plant's apparent lack of a concrete way of organizing it's stem 
allowing it to branch this way?  Are kiwi fruit plants sympodial, 
monopodial, or something else.  What is happening?!
Any info is much appreciated.



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