Nostoc verrucosum is a species of cyanobacteria usually found in colonies and in globose racks. It has a greenish to blackish color. It grows in creek beds, shallow streams, waterfalls, and moist understory in rain forests, in alkaline soil and water habitat. Colonies are velvety to the touch.

Like other Nostoc

Nostoc

Nostoc is a genus of cyanobacteria found in a variety of environmental niches that forms colonies composed of filaments of moniliform cells in a gelatinous sheath.The name "Nostoc" was invented by Paracelsus...

species, this organism fixes nitrogen

Nitrogen fixation

Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen in the atmosphere is converted into ammonia . This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g., nucleotides for DNA and RNA and...

 and provides important nutrients for plants, forming a symbiotic

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...

 interaction with them. It can withstand freezing and thawing cycles and can survive extreme conditions in places such as the Arctic

Arctic

The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

 and Antarctica. It can stay dormant for long periods of time and abruptly recover metabolic activity when rehydrated. Like all other procaryotic organisms, it is without organized nucleus

Cell nucleus

In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...

 and 70%-85% of its cytoplasm

Cytoplasm

The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...

is water.