This colony of lichens is found at the edge of the basalt cliffs of Widan el Faras, near the ancient quarries along the northern edge of the Fayum depression. While normally the flora of the oases and their near environs is not included in this listing, technically the location is within the Libyan Desert, and the uniqueness warrants the inclusion of this species.
No lichens were noted in any other area of the Libyan Desert (though common in the more humid western part of the Sahara), the presence of this thriving colony, observed continuously since 2001, is probably due to a very special microclimate. We have noted thick fog along the Cairo - Baharya road several times, and the location is just 20 kilometres from the road. Probably this small spot, no more than 50 metres long along the cliff edge, produces more and thicker fog supporting the colony.
(Identification by Imre Friedmann & Chris McKay)
Widan el Faras (northern Fayum), March 2005
Cairo - Baharya road (north of Fayum), November 1997