How Do You Identify Strange Growths On A Quaking Aspen Tree?
Quaking aspen, with its mottled, ghost-white trunk and tremulous leaves, turning brilliant gold in autumn, is one of the most striking of North America’s trees. Common in the Rockies, the ranges of the intermountain West and northern forests, aspens have soft, easily wounded bark. Cankers are the most common mortal affliction. Notice large, dark deformities of folded, whorled bark, and the aspen may be suffering from black canker, a frequent malady. The cankers often contain wood-boring insects. Watch for shallow sunken areas of irregular border, the early signs of Hypoxylon canker infection. Inner cambium, revealed when outer bark dies and falls away, is dark and disintegrative, and the infected area may manifest a checkerboard pattern. Look for the charred-looking inner cambium of sooty-bark cankers. Often beginning as shallow depressions in the bark, these cankers may expand several feet in a single year. Outer bark eventually falls away, exposing the ravaged black interior bark wit
