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.
(yellow) Teloschistes exilis Bastrop, TX March 26, 2009 When Kenny and I went to Central Texas during Spring Break of 2009, I was amazed at the incredible variety of lichens I saw on the trees and rocks! There were lots of twigs on the ground with mixtures of lichens on them due to a wind storm earlier that morning.
Great Smoky Mountains NP Feb. 22, 2009 These flat-branched lichens are commonly found growing on tree bark. Larger specimens have round, flat apothecia on the ends of the branches. The scientific names of some of the lichens are fun to say, like "Ramalina"!
