GNARLED.

Gnarled, I like this word which we owe to Shakespeare, who created it in 1603 in "Measure for Measure." He writes," Thy sharpe and sulphurous bolt splits the unwedgable and gnarled oak."  The word gnarled didn't come into use again until the 19th century and is believed to be related to the Middle English word "knar" meaning knot.  Not a lot of people knew that, including me !