Mappa burl is the burl of the European black poplar tree (Populus nigra, of the family Salicaceae, the willow family), so you won't see mappa as anything other than a burl. My thanks to Marcus Starbuck for alerting me to this, and my thanks to Paul van Rijckevorsel for telling me that "mappa" is a contraction of the German “Maser Pappel” (“poplar burl”)
my samples:
burl veneer
burl veneer and closeup
web pics
bookmatched thinwood pair
solid burls
solid burls all from the same vendor
veneer with wet and dry sections
burl veneer
this was a particularly large piece of mappa burl --- judging from the context of the pic from which I extracted this section (which is about 5' long) the whole sheet was about 8' long a 2.5" wide
bookmatched burl veneer
burl veneer all from the same vendor --- I believe that the extreme color variation between the white smooth areas and the reddish burl-eye areas, is somewhat due to image manipulation and not inherent in the wood. See my veneer samples at the top of the page for what is probably a more realistic illustration of the veneer.
bookmatched burl veneer
quartermatched burl veneer
bowl --- this is the only solid object I've ever encountered of mappa
