The white oaks have conducting and non-conducting sapwood.
http://www.treedictionary.com/DICT2003/S/sapwood.html

The current growth increment is the only one that is not plugged with
tyloses.
http://www.treedictionary.com/DICT20...20vessels.html

All other sapwood increments are plugged. Oaks are heartwood forming trees.
The red oak has all conducting sapwood and forms traumatic tyloses when
wounded. You could take a cookie of each and spit on it and blow through.
The red oak will bubble all increments of sapwood unless wounded. The white
oak will only show bubbles in the current growth increment. You can look
these things up in the dictionary. I will go back and add some links for
you.

John

"enigma" wrote in message
. ..
"symplastless" wrote in
:

I do not have all the answers. So in that respect a bur
oak is similar to a red oak. Very interesting. I learn
something new everyday. I believe the vessel arrangement is
similar to white oak with tyloses plugging all but the
current growth increment. Can you verify that Lee?

i believe so. it's been awhile since i read up on the oak
family, but i think they all form tyloses.
the burr oak is a pretty interesting tree. i have a few on my
NY property, but they don't grow at all in my area of NH.
lee
--
Last night while sitting in my chair
I pinged a host that wasn't there
It wasn't there again today
The host resolved to NSA.