Acotyledones, Jussieu.—Exembryonatae or Arhizae, Richard; Agamae or Atheogamae, Auctorum; Nemeae, Fries.
Characters.—Sexual organs, and, consequently, flowers and true seeds, absent. Reproduction taking place either by spores, which are enclosed in cases called thecae, or imbedded in the substance of the plants; or else by a mere dissolution of the utricles of cellular tissue. Spores destitute of embryo and cotyledons, germinating at no fixed point, but at any part of their surface.
The Elements of Materia Medica and Therapeutics, Vol. II, 3th American ed., was written by Jonathan Pereira in 1853.