Lecidea hassei (Hasse's lecidea lichen) is an endolithic lichen that appears as tiny black, gray rimmed, plate-like or crinkled discs between crystals of rock in California.

[1] It is endemic to California, where it only grows in the lower montane belt, including in deserts and chaparral.

[3] The sexual reproduction structures (apothecia) are black, thinly rimmed (70–100 μm ) with unpigmented fungal tissue surrounding black discs in the middle, and up to 2.2 mm in diameter.

[1] They rise out of the rock in a flat to convex disc with a constricted base,[1] giving the appearance of tiny raised plates.

It grows in open areas on granite, schist, and other acidic rock.