Dichanthelium lanuginosum (Panic grass) is a species of grass

Grass

Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...

. It grows in geothermal

Geothermal

Geothermal is related to energy and may refer to:* The geothermal gradient and associated heat flows from within the Earth- Renewable technology :...

 areas of Yellowstone National Park

Yellowstone National Park

Yellowstone National Park, established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872, is a national park located primarily in the U.S. state of Wyoming, although it also extends into Montana and Idaho...

, USA. It is able to withstand high temperatures and high acid

Acid

An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

ity in its rhizosphere

Rhizosphere

The rhizosphere is the narrow region of soil that is directly influenced by root secretions and associated soil microorganisms. Soil which is not part of the rhizosphere is known as bulk soil. The rhizosphere contains many bacteria that feed on sloughed-off plant cells, termed rhizodeposition, and...

. In 2007 it was found that the heat tolerance is conferred to the grass by a symbiosis

Symbiosis

Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...

 between a fungus

Fungus

A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...

 and a virus

Virus

A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

. When it is colonised by the fungus Curvularia protuberata

Curvularia protuberata

Curvularia protuberata is a species of fungus in the Pleosporaceae family. It forms a mutualistic relationship with Dichanthelium lanuginosum and Curvularia thermal tolerance virus that allows the grass to grow in soils that are far warmer than it normally tolerates. The mutualism allows the grass...

and the fungus is in turn colonised by a particular virus, the grass is able to tolerate soil temperatures of up to 65°C that would otherwise be lethal.