Cryptogamia (kr?pt?-g?m?-?), n.; pl. Cryptogamiæ (-&unr_;). [NL., fr. Gr. kryptos hidden, secret + gamos marriage.] (Bot.) The series or division of flowerless plants, or those never having true stamens and pistils, but propagated by spores of various kinds.
[1913 Webster]

&hand_; The subdivisions have been variously arranged. The following arrangement recognizes four classes: --
I. Pteridophyta, or Vascular Acrogens. These include Ferns, Equiseta or Scouring rushes, Lycopodiaceæ or Club mosses, Selaginelleæ, and several other smaller orders. Here belonged also the extinct coal plants called Lepidodendron, Sigillaria, and Calamites.
II. Bryophita, or Cellular Acrogens. These include Musci, or Mosses, Hepaticæ, or Scale mosses and Liverworts, and possibly Characeæ, the Stoneworts.
III. Algæ, which are divided into Florideæ, the Red Seaweeds, and the orders Dictyoteæ, Oösporeæ, Zoösporeæ, Conjugatæ, Diatomaceæ, and Cryptophyceæ.
IV. Fungi. The molds, mildews, mushrooms, puffballs, etc., which are variously grouped into several subclasses and many orders. The Lichenes or Lichens are now considered to be of a mixed nature, each plant partly a Fungus and partly an Alga.
[1913 Webster]