''Clavascidium lacinulatum'' is a dark brown

squamulous A squamulose lichen is a lichen that is composed of small, often overlapping "scales" called squamules. If they are raised from the substrate and appear leafy, the lichen may appear to be a foliose lichen, but the underside does not have a "skin ...

terricolous A terricolous lichen is a lichen that grows on the soil as a substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is at ...

lichen.Lichen Flora of the Greater Sonoran Desert Region. Vol 1, Nash, T.H., Ryan, B.D., Gries, C., Bugartz, F., (eds.), 2001

/ref>Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, In

Joshua Tree National Park Joshua Tree National Park is an American national park in southeastern California, east of San Bernardino and Los Angeles and north of Palm Springs. It is named after the Joshua trees (''Yucca brevifolia'') native to the Mojave Desert. Original ...

, it is the most common of the

biological soil crust Biological soil crusts are communities of living organisms on the soil surface in arid and semi-arid ecosystems. They are found throughout the world with varying species composition and cover depending on topography, soil characteristics, climate, ...

lichens.Photo Gallery, Joshua Tree Lichens, National Park Service
/ref>

References

Lichen species Verrucariales Taxa named by Erik Acharius Lichens described in 1810 {{Eurotiomycetes-stub