Deal -- there is no such thing as a "deal tree".  Deal is the term used
historically for general constructional timber.  In days gone by you
used to get some good quality pine under this description.  Nowadays
most general constructional timber is full of knots with a grain that
wends its way in all directions and may eventually get to the end of
the plank, if it hasn't come out of the side on the way!

Best wishes from GB,  Nicholas Simons.