''Trapeliopsis steppica'' is a species of

squamulose lichen 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 "ski ...

in the family

Trapeliaceae Trapeliaceae is a family of lichens in the order Baeomycetales. The family contains 12 genera and about 125 species. Taxonomy Trapeliaceae was originally circumscribed by French lichenologist Maurice Choisy in 1929. Hannes Hertel emended the f ...

. It is found in the western United States, where it grows on soil in grassland and in shrub–steppe.

Taxonomy

The lichen was formally described as a new species in 2003 by

Bruce McCune Bruce Pettit McCune (born 1952) is an American lichenologist, botanist, plant ecologist, and software developer for analysis of ecological data. Biography McCune grew up in Cincinnati. He completed his freshman year of college at Lawrence Univers ...

and Francisco Camacho. The type specimen was collected from Horse Heaven Hills in Benton County, Washington. Here it was found growing on soil in a

bunchgrass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perennial ...

( bluebunch wheatgrass, ''Pseudoroegneria spicata'')

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grasslands, ...

. This habitat is alluded to in its

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

, ''steppica''.

Description

''Trapeliopsis steppica'' has a squamulose (scaly) thallus that is light- to medium-gray in color. The individuals squamules comprising the thallus are rounded to elongated, 0.15–0.50 mm thick and 0.5–1.5 mm long. Soredia are usually present on the thallus surface; they are dark gray to greenish-black to black, organized into regions of rounded

soralia Soredia are common reproductive structures of lichens. Lichens reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungal hyphae wrapped around cyanobacteria o ...

. Although morphologically similar to ''

Trapeliopsis californica ''Trapeliopsis'' is a genus of lichenized fungi in the family Trapeliaceae. It contains 20 species. The genus was circumscribed in 1980 by Hannes Hertel and Gotthard Schneider, with '' Trapeliopsis wallrothii'' designated as the type species. S ...

'', ''T. steppica'' can be distinguished from that species by the presence of soralia that is dark and rounded, and a thinner upper cortex.

Habitat and distribution

In addition to Washington, ''Trapeliopsis steppica'' has also been recorded from eastern Idaho south to southern California, in grassland and in shrub–steppe. It is most common in areas that have been little affected by grazing. The lichen has also been reported as a common lichen component 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, ...

of sagebrush habitats in southwest Idaho.

References

{{Taxonbar, from=Q10701404 Baeomycetales Lichen species Lichens described in 2002 Fungi of the United States Taxa named by Bruce McCune Fungi without expected TNC conservation status