CHAPTER X. 



POLYPODIUM, Linnceus. 



(Pol-yp-od'-i-um.) 



Polypodies. 



OLYPODIUM, the Greek name used by Theophrastus, is applied 

 to plants wHcli, in Hooker and Baker's " Synopsis Filicum," 

 form Genus 48 ; it is derived from polys, many, and podion, 

 a little foot, in allusion to the appearance of the rhizomes 

 and their appendages with which the majority of these plants 

 are provided. The genus is an exceedingly large one — undoubtedly the most 

 extensive of the Natural Order Filices (Ferns), and includes plants of two 

 totally different modes of growth, each series comprising a number of species 

 of each of the different kinds of venation and from all climates. Eaton, in 

 his exhaustive work on "Ferns of North America" (vol. i., p. 116), says: 

 " Mr. John Smith, former Curator of the Royal Botanical Gardens, Kew, has 

 described and carefully distinguished the two modes of growth noticed in 

 Polypodium, under the names of ' Eremobryoid ' and ' Desmobryoid.' In the 

 Eremobrya each frond springs from a separate node, more or less distant 

 from its neighbour, and is there articulated with the rhizome ; so that, when 

 it has passed its maturity, it separates at the node, and leaves behind a clean, 

 concave scar, as may readily be noticed in P. aureum. The essential distinction 

 between the Eremobrya and the Desmobrya rests in the fronds of the former 

 being articulated with the axis or rhizome, while those of the latter are 

 adherent and continuous with the axis or rhizome." In the Desmobrya the 

 spores are always medial on the veins, while in the Eremobrya, which 



