The Collaborative International Dictionary
The Age of Acrogens
Acrogen \Ac"ro*gen\, n. [Gr. 'a`kros extreme, high + -gen.] (Bot.) A plant of the highest class of cryptogams, including the ferns, etc. See Cryptogamia.
The Age of Acrogens (Geol.), the age of coal plants, or the carboniferous era.