Crustose, foliose and fruticose lichens of the Namib Desert

Dirk Heinrich 

A rock the size of a head, covered with lichens, is like a little colourful garden. The Lüderitz Cobblestone lichen (Acarospora luederitzensis) forms a yellow mosaic pattern to the surface of the rock. The grey Herero lichen (Santessonia hereroensis) on the other side, looks like a small shrub without leaves, surrounded by Lecanora panis-erucae, a rim lichen species which looks like white gravel. 

North of Wlotzkasbaken, a field of an orange shimmer can be seen. A closer look reveals thousands of fruticose Cape Hair lichen (Teloschistis capensis), which cover many square kilometres in the Namib Desert. Lichens are not said to be plants but rather a symbiosis of tubular mushrooms and blue-green algae. The mutually advantageous relationship between the mushroom and the algae allows the lichen to exist there. Professor Volkmar Wirth, an experienced lichenologist and the author of Lichens of the Namib Desert – A guide to their identification, explains that “categorisation is an easy way to describe the different shapes of lichen, but due to their transitions and forms it is very difficult to apply these terms”.  

According to Professor Wirth there are about 250 species of lichen in the Namib Desert. In the entire country, it is probably more than 1,000 species. A very large number of lichen species has not been identified yet, as it's not an easy task. It often requires an analysis of the substances and a microscopic examination.