Acarospora schleicheri, the soil paint lichen, is a bleached to bright yellow areolate to squamulose lichen that commonly grows to 100NaN0 on soil (terricolous) in arid habitats of southern California and Baja California, also in Europe and Africa.[1] [2] It produces rhizocarpic acid as a secondary metabolite,[2] which gives it a yellow coloration and serves to protect it from the sun. Its lower surface is also yellow.[2] It can be greenish when moist.[1] Roundish, angular, or irregularly shaped squamules are 0.5–4 mm in diameter.[2] There are 0–1 (sometimes 2–3) apothecia embedded in the thallus, with 0.4–1.2 mm roundish black to reddish-brown,[2] or dark brown[1] discs, which sometimes fill the areola so as to be lecanorine.[2] It divides vegetatively on the soil.[2] Asci are club shaped (clavate) and have 100 or more spherical to ellipsoid spores.[2] Lichen spot tests are negative, and it is UV+ orange under ultraviolet light.[1]