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AN ENUMERATION 



CULTIVATED FERNS. 



Obder L— pilices. 



Fronds circinately unfolding, -uniform and leafy, bearing 

 sporangia on their under side or margin (rarely on both aides) ; 

 or of two forms, one leafy and sterile, the other wholly, or some 

 portion of its segments moire or less contracted and fertile. 

 Sporangia membraneous, one-celled, free, furnished with a 

 vertical, horizontal, or oblique articulated elastic ring. 



Sub-Obdee I.— POLYPODIACEJE. 



Sporamgia globose or oval, unilocular, pedicellate or sessile, 

 membraneous, furnished with a vertical ring, and opening at a 

 right angle to the direction of the ring. 



Division I. — Eremobrya. 



Fronds in vernation lateral, solitary, attached to the axis 

 (rhizome) by a special articulation. 



* Sori indusiate. 



Tribe I.-OLEANDRE^. 



Son round, medial. Indusivm, lateral, interiorly attached or 

 sometimes central, plane. 



