Also soredia can be removed while repelling raindrops. Isidia also consists of a cluster of photobiont cells surrounded by fungal filaments which are enclosed by a protective cortex layer. Isidia is scattered on the thallus outer surface. When isidia is detached from the thallus, a new lichen is formed. Fragmentation of the lichen generates a new lichen body.
Fragmentation usually occurs most often in fruticose lichen.
Usually fragmentation occurs by strong winds, which tear and then disperse the fragment.