The Ash Burl is a trunk burl and forms in the trunk of the tree, rather than a root burl like Walnut.  Typically, Ash Burl will not be sound.  In other words, it will include tiny bark pockets, sometimes not so tiny, and open holes.  The Burl pattern itself tends to be clustered around the veneer sheets mixed in with swirly grain.  It is rare to find large dimension sheets, truly sound, with consistent burl patterning.  And as these burls are sliced on a full round, a lathe, the goal is to achieve as much veneer with the whitish color before the “olive” colored heartwood comes in.  Ash burl is mainly used on furniture and in the dash board industry.  This veneer stains and dyes very well.