Turn of the Screw

Barry Meyers-Rice (barry@mips3.as.arizona.edu)
Mon, 1 Aug 1994 21:29:12 +0700

>I took a walk in the woods today and checked the petiole twist of the
>leaves of Quercus laevis. The twist is in both directions and
>approximately equal in number in each direction. I looked at about a
>dozen trees. It appears to be randomly chosen.


Hmm. Well, the lamina of this _D.chrysolepsis_ are all in the same direction.
Very strange.

In one sense I shouldn't be really surprised at this---after all spirals are
certainly not rare in nature. Many plants have a spiral phyllotaxy and all
but one of the Utricularia that have twining inflorescences spiral in the
same direction. Still, it's neat to see.

I gather that both Gordon Snelling and Tom Johnson will be coming through
Tucson this week. I'll have both look at this plant to tell me if they
see what I'm talking about. Perhaps I'm just going mad.