''Syntrichia caninervis'', also known as steppe screw moss, is a desert moss species distributed throughout the world. As an

extremophile An extremophile () is an organism that is able to live (or in some cases thrive) in extreme environments, i.e., environments with conditions approaching or stretching the limits of what known life can adapt to, such as extreme temperature, press ...

, it is able to withstand desiccation under dry conditions with little access to water and is commonly found in hypolithic communities. It makes use of a novel adaptation to the desert environment to harvest and collect water sources such as dew, fog, snow, and rain, using tiny hairs instead of roots. In laboratory experiments, ''S. caninervis'' has shown the ability to survive in a simulated

Martian Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. Trends in the planet's portrayal have largely been influenced by advances in planetary science. It became the most popular celes ...

environment.

Description

The plant was first described by English bryologist

William Mitten William Mitten (30 November 1819 – 20 July 1906) was an English people, English pharmaceutical chemist and authority on bryophytes who has been called "the premier bryologist of the second half of the nineteenth century". He built up a colle ...

(1819–1906) to the

Linnean Society of London The Linnean Society of London is a learned society dedicated to the study and dissemination of information concerning natural history, evolution, and Taxonomy (biology), taxonomy. It possesses several important biological specimen, manuscript a ...

in May 1858, with a description published in their journal in February 1859. It belongs to the '' Syntrichia'' genus and the Pottiaceae family. It is commonly known as steppe screw moss.

Distribution and habitat

''S. caninervis'' has a widespread global distribution and is an

commonly found in extreme desert environments and hypolithic communities with the capacity to withstand desiccation under dry conditions. It has been observed growing in China, Mongolia, Siberia, central and southwestern Asia, Europe, and North America. Se
distribution map
. In

Tibet Tibet (; ''Böd''; ), or Greater Tibet, is a region in the western part of East Asia, covering much of the Tibetan Plateau and spanning about . It is the homeland of the Tibetan people. Also resident on the plateau are other ethnic groups s ...

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

, and circumpolar regions, it is part of the biological soil crust, which is a resilient type of ground cover often found in arid lands. In North America, the plant is found throughout the western and northwestern United States and in two western Canadian provinces. In the United States, it is found as far east as New Mexico, Colorado, Wyoming and Montana, all the way through Idaho, Utah, Arizona, and Nevada, and as far west as California, Oregon, and Washington. Two of the most common plant communities in the United States are found in the

Mojave Desert The Mojave Desert (; ; ) is a desert in the rain shadow of the southern Sierra Nevada mountains and Transverse Ranges in the Southwestern United States. Named for the Indigenous peoples of the Americas, indigenous Mohave people, it is located pr ...

and in the Columbia River drainage basin. In Canada, it is found in British Columbia and Alberta.

Extremophile characteristics

Drought tolerance

''S. caninervis'' is well-known for its ability to tolerate drought conditions, making it well-adapted to

desert A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the la ...

environments. Among these adaptions is its tiny hairs on the leaves that allow it to exploit multiple different sources of water, such as dew, fog, snow, and rain. Another example is its ability to photosynthesize once remoistened after desiccation.

Extreme temperature tolerance

Research has shown that ''S. caninervis'' can survive freezing temperatures as low as (in

liquid nitrogen Liquid nitrogen (LN2) is nitrogen in a liquid state at cryogenics, low temperature. Liquid nitrogen has a boiling point of about . It is produced industrially by fractional distillation of liquid air. It is a colorless, mobile liquid whose vis ...

) for up to 30 days. It has also demonstrated the ability to withstand storage at for up to 5 years. In both cases, the

moss Mosses are small, non-vascular plant, non-vascular flowerless plants in the taxonomic phylum, division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Wilhelm Philippe Schimper, Schimp. 1879) may also refer to the parent group bryo ...

was able to regenerate upon thawing, with dehydrated specimens showing faster recovery compared to hydrated ones.

Radiation resistance

''S. caninervis'' exhibits remarkable tolerance to

gamma radiation A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...

. It can survive exposure to doses of up to 500 Gy, which is lethal to most plants and far exceeds the

lethal dose In toxicology, the lethal dose (LD) is an indication of the lethal toxicity of a given substance or type of radiation. Because resistance varies from one individual to another, the "lethal dose" represents a dose (usually recorded as dose per kilog ...

for humans (around 50 Gy). Some studies have even suggested that exposure to 500 Gy of gamma radiation may promote the plant's growth.

Simulated Martian conditions

In laboratory experiments, ''S. caninervis'' has demonstrated the ability to survive simulated

conditions. These conditions included an atmosphere composed of 95% CO₂, temperature fluctuations between , high levels of

UV radiation Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of t ...

, and low

atmospheric pressure Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1,013. ...

. Dried moss plants achieved a 100% regeneration rate within 30 days after being subjected to these conditions for up to 7 days. *

Varieties

The

Global Biodiversity Information Facility The Global Biodiversity Information Facility (GBIF) is an international organisation that focuses on making scientific data on biodiversity available via the Internet using web services. The data are provided by many institutions from around th ...

lists the following five varieties for ''Syntrichia caninervis'':"Syntrichia caninervis Mitt."
. Global Biodiversity Information Facility. Retrieved July 7, 2024. *''Syntrichia caninervis'' var. ''abranchesii'' (Luisier) R.H.zander *''Syntrichia caninervis'' var. ''astrakhanica'' Ignatov, Ignatova - Suragina *''Syntrichia caninervis'' var. ''caninervis'' Mitt. *''Syntrichia caninervis'' var. ''gypsophila'' (J.J.Amann ex G.Roth) Ochyra *''Syntrichia caninervis'' var. ''pseudodesertorum'' (Vondr.) M.T.Gallego

References

{{taxonbar, from=Q15316097 Extremophiles Pottiaceae Plants described in 1877 Taxa named by William Mitten