Glossary
Glossary of Terminology of Wood according to Ed Rode:
Burl
Burl is sometimes referred to as Burr across the pond. This is an abnormal growth on a tree that is filled with small knots from dormant buds resulting from some kind of stress to the tree. Air burl can be a node projecting from the trunk or branch anywhere from ground level to considerably high up on the tree. Root burl grows beneath the ground and is attached to the roots and is most often not discovered until the host tree is either harvested or downed by natural means. Because of burl’s rarity and exceptional beauty the cost is so great it is often seen in the form of veneers such as luxury automobile dashboards. Solid pieces are valued by wood turners and furniture makers.
“I treat exceptional burls as the precious things they are and afford them all the attention they both require and deserve. Because of the extremely irregular grain this usually translates to a great deal more time in stock preparation and finishing.” – Ed Rode
Crotch
Crotch is figuring that occurs where two branches or the trunk and a branch grow together creating a plume like appearance. Most hardwood trees have crotches but very many are not usable. Walnut and mahogany are two species that can produce quite beautiful examples of this phenomena. Drying of the wood is problematic as the crotch figure dries at a different rate that the face of the rest of the board.
Spalting
Spalting is a pattern caused by fungus growing in a log or tree. The resulting black streaks usually grow with the grain and can interconnect creating a fascinating marbling. There is a very fine line timewise between the harvesting of a sound log and one that is punky and useless once spalting has begun.
Wormed/Ambrosia
Wormed or Ambrosia wood is when normal soft maple trees are infested by the ambrosia beetle. Small tunnels are bored into the tree allowing a fungus to enter creating the notable black and gray streaks around each tunnel and the adjacent wood. This unique figuring does not adversely affect the wood for furniture building purposes.
Curly
Curly is a hereditary factor in some trees that causes compression waves. These patterns in the wood can often appear to be holographic and take on a three dimensional quality. Depending on the intensity and the spacing of the “kink” a remarkable chatoyance can occur and is often referred to as tiger stripe. When the log is quarter sawn and has intense curl in might be called fiddle back and is treasured by instrument makers.
Quilted
Quilted is certainly among the rarest and therefore the most valuable of figuring. In flat sawn boards quilting appears like large molten bubbles in the grain or cross sections of sausage and is used sparingly in only the most high quality applications such as yacht and airplane interiors, luxury auto dashboards, musical instruments and gun stocks.