On 18/09/18 19:08, Chris Hogg wrote:
On Tue, 18 Sep 2018 18:53:16 +0100, Jeff Layman
wrote:

Many years ago we had an old cypress (probably C. lawsoniana) cut down.
The trunk was cut into rounds which were left to dry out for use in our
log-burning stove.

I've just got round to splitting the rounds and to say it has been
difficult is a bit of an understatement!. Basically, the wood was still
pretty tough (no splits on drying), but, even allowing for that, when
split through the pieces did not separate. On close examination, there
were what looked like several "internal branches" through the centre of
the wood, acting a bit like rebars in concrete. In the end I used a
chisel to cut through them. See photos he

https://imgur.com/a/FTRBaXc

The first shows the "rebars" cut through each side of the split. The
second shows the varying angles they take (see top right one in
particular). The third shows each side of a split log showing the path
of the "rebar".

Anyone seen anything like this before? What are they?

Surely they are the remains of side branches that, if not apparent on
the surface, have snapped off at an earlier stage of the tree's
growth, and the stumps have been overgrown by the expanding trunk so
that they are no longer visible on the outside, in much the same way
as a trunk will 'swallow' fence wire or nails etc or even bicycles!
https://tinyurl.com/y9fbupgy

I didn't think of that! They do look like branches, but why have I never
noticed them before when splitting other cypress, birch, cherry, sorbus,
etc? I can understand metal from bicycles and other objects remaining in
trees, but I would have thought a tree would have been able to recycle
its own lignin into something usable. Or, if not, form a callous at the
growth point and allow the rest to drop off.

Or am I missing the plot completely and these, in sawn wood, form the knots?

--

Jeff