Botany Curator

October 20, 2016
Norway Maple leaves with typical "tar spot"

 By Marian Munro

Dozens of folks over the years have asked about the black spots on the maple trees around the city of Halifax-Dartmouth. These sooty black marks are rarely seen on only one tree. Usually all maples nearby will enjoy these additional adornment. Their presence indicates an infection by a fungus in the genus Rhytisma. Healthy trees can withstand these attacks, although heavy infestations can cause the tree to lose leaves early.