Steppe Screw-Moss

The plant was first described by English bryologist William Mitten (1819–1906) to the Linnean Society of London 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.

S. caninervis has a widespread global distribution and is an extremophile 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. In Tibet, Antarctica, 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 and in the Columbia River drainage basin. In Canada, it is found in British Columbia and Alberta.