434 PHARMACEUTICAL BOTANY 
of fronds are produced, sterile fronds which represent green foliage 
leaves and fertile fronds which contain little or no chlorophyll and 
bear clusters Of sporangia. 
There are two sub-classes of Filicineze, viz.: 
SuB-cLass EusPORANGIAT&, including ferns like Ophioglossum 
or adder’s tongue and Botrychium or moonwort in which the 
sporangium originates from a group of epidermal cells and 
2h 
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Fic. 326.—Fern leaves, showing various degrees of subdivision or branching of the 
blade. A, Phyllitis; B, Polypodium; C, Pteris; D, Adiantum. (From Gager.) 
contains similar spores, the latter giving rise to prothallia which 
bear both antheridia and archegonia. 
Susp-cLass LEPTOSPORANGIAT& which include most of the 
common ferns and the water ferns. In these the sporangium 
develops from a single epidermal cell. Most of them have 
sporangia containing similar spores but the water ferns are 
heterosporous. 
Orver 1.—FivicaLes or TRuE Ferns (Homosporous) 
Famity CyATHEACE®.—Mostly tree-like ferns of the tropics 
and subtropics possessing sporangia with a complete annulus. 
