A new cyanobacterial lichen species, Peltula inversa (Lichinales, Peltulaceae), growing on the lower part of quartz pebbles, where they contact the surrounding soil (= hypolithic), is described here. The internal morphology of the new species is inverse, exposing the cyanobiont layer towards the translucent quartz rock. Only a very small part of the thallus is exposed to the soil surface and then black-olive colored. When seen from above, sterile and fertile parts of the thallus surround the quartz pebble as a clearly visible black rim with reddish-brown apothecia. This peculiar growth form of a lichen is being interpreted here as an adaptation to high irradiance and water shortage.