Aspicilia cyanescens (bluish sunken disk lichen) is a rough surfaced, bluish-tinged pale gray rimose to areolate crustose lichen, endemic to California.
[1]: 226 It is unique among California members of its genus in that it can sometimes be found on growing on bark or wood, especially incense cedar and sometimes on white fir or giant sequoias in the central Sierra Nevada range and southern California mountains.
[1]: 226 Each areole commonly has 1–7 roundish to angular apothecia that are 0.1–1.3 mm in diameter.
[2] Apothecia have black to blue-black, concave to flat discs, without pruina.
[2] Lichen spot tests are all negative.