While burl is a tree deformity, it can come in some beautiful patterns that makes it valuable to wood workers. Here's Hunski Hardwoods description of burl on its website: A burl is a tree growth ...

University of Arkansas, Fayetteville. "Tree-ring data show history, pattern to droughts." ScienceDaily. ScienceDaily, 17 February 2013. <www.sciencedaily.com / releases / 2013 / 02 / 130217083054 ...

Roger Earl Latham, Robert E. Ricklefs, Global Patterns of Tree Species Richness in Moist Forests: Energy-Diversity Theory Does Not Account for Variation in Species Richness, Oikos, Vol. 67, No. 2 (Jun ...