Nostoc is a genus of cyanobacteria found in various environments that forms colonies composed of filaments of moniliform cells in a gelatinous sheath. The name Nostoc was coined by Paracelsus. Nostoc can be found in soil, on moist rocks, at the bottom of lakes and springs, and rarely in marine habitats.

What is the English meaning of Nostoc?

nostoc in American English

(ˈnɑstɑk) noun. any freshwater, blue-green alga of the genus Nostoc, often occurring in jellylike colonies in moist places.

Why Nostoc is known as fallen stars?

When on the ground, a Nostoc colony is ordinarily not seen; but after a rain it swells up into a conspicuous jellylike mass, which was once thought to have fallen from the sky, hence the popular names, fallen star, star jelly, Sternschnuppen (shooting stars), troll's butter and witch's jelly.