Diagram of the Cross-section of an Usnea strigosa lichen branch
Oak Ridge, TN January 28, 2009 This strange lichen likes to grow on Maple trees. We have Silver Maples (unfortunately!) in our yard, it is very common to find this strange lichen on the ground after a windy day. Lichens just use tree bark as a substrate to grow on, they do not damage the tree. The flat, fringed patches are the reproductive bodies, called apothecia.
The Usnea species of lichens have a central core made up of hyphae strands called the axis; it gives the branches rigidity. This core can be revealed by gently pulling the green cortex and medulla layers off. The axis is an identifying characteristic for this genus.
