''Amandinea punctata'' (tiny button lichen) is a

crustose Crustose is a Habit (biology), habit of some types of algae and lichens in which the organism grows tightly appressed to a substrate, forming a biological layer. ''Crustose'' adheres very closely to the Substrate (biology), substrates at all poin ...

brown to gray

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

that grows on wood and rock around the world.Amandinea punctata in the Joshua Tree National Park (California, U.S.A.) Map collection: Kerry Knudsen, Kocourková Jana; Czech University of Life Sciences Prague, Faculty of Environmental Sciences, Department of Ecology, Czech Republic; 2012 It grows on, not in the wood (

epiphytic An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...

). It prefers bark that is

acidic An acid is a molecule or ion capable of either donating a proton (i.e. hydrogen cation, H+), known as a Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis acid. The first category of acids are the ...

. In

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, it is among the most common crustose lichens occurring on trees. Sometimes its

thallus Thallus (: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. A thallus usually names the entir ...

is absent, and branches may be covered in its

lecideine A lichen ( , ) is a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualistic relationship.

apothecia An ascocarp, or ascoma (: ascomata), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. As ...

. Because of its tolerance of low humidity, it is one of the few epiphytic lichens growing on trees in California deserts, where it commonly grows on the old, dry wood of

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' ( ) of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere as far south ...

s, and sometimes fallen

pinyon pine The pinyon or piñon pine group grows in southwestern North America, especially in New Mexico, Colorado, Arizona, and Utah, with the single-leaf pinyon pine just reaching into southern Idaho. The trees yield edible Pine nut, nuts, which are a sta ...

s and

oak An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

s, or on their dead branches. Compared to other lichens, it is tolerant of

air pollutants Air pollution is the presence of substances in the air that are harmful to humans, other living beings or the environment. Pollutants can be gases like ozone or nitrogen oxides or small particles like soot and dust. It affects both outdoor air ...

and other toxins such as NO₂ and SO₂.

References

punctata Lichen species Lichens described in 1796 Lichens of Europe Lichens of North America Taxa named by Georg Franz Hoffmann {{Caliciales-stub