Word Study
nostoc
CIDE DICTIONARY
nostoc, prop. n. [F.].
A genus of algæ. The plants are composed of moniliform cells imbedded in a gelatinous substance. [1913 Webster]
" Nostoc commune is found on the ground, and is ordinarily not seen; but after a rain it swells up into a conspicuous jellylike mass, which was formerly supposed to have fallen from the sky, whence the popular names, fallen star and star jelly . Also called witches' butter ." [1913 Webster]
OXFORD DICTIONARY
nostoc, n. any gelatinous blue-green unicellular alga of the genus Nostoc, that can fix nitrogen from the atmosphere.
Etymology
name invented by Paracelsus
For further exploring for "nostoc" in Webster Dictionary Online