CHAPTER XXVI, 



ASPIDIUM, Swam. 

 (As-pid'-i-um.) 



Buckler or Shield Ferns. 



HE name of this popular genus is derived from aspidion, a little 

 buckler or shield, in allusion to the form of the indusium or 

 covering of its sori (spore masses). Aspidium is Genus 43 

 of Hooker and Baker's " Synopsis Filicum," and it forms 

 a very interesting portion of the tribe Aspidiece. It is a genus 

 of a particularly cosmopolitan nature, comprising, as it does, several British 

 as well as numerous exotic species, and showing a very extensive variation as 

 regards size, texture, cutting, and venation. Thus we have in the same 

 genus some species, such as A. (Polystichum) lachenense and A. (P.) Thomsoni, 

 of small, and others, such as A. (P.) anomalum and A. (P.) ascendens, of 

 gigantic, dimensions ; and though the majority of Aspidiums are, like all the 

 known Cyrtomiums, of a particularly coriaceous (leathery) texture, some 

 kinds, such as A. (Polystichum) glandulosum, A. (Cyclopeltis) semicordatum, 

 A. (Polystichum) sikkimense, and others, are nevertheless remarkable for the 

 softness of their foliage. Again, a great contrast exists between species like 

 A. (Polystichum) foenieulaccum, A. (P.) laserpitiifolium, and A. (P.) multijidum, 

 with finely-divided, and others with broad, fronds, such as A. (Euaspidium) 

 platanifolium, A. (E.) trifoliatum, &c. ; and while their veins in certain 

 groups are all free, in others they are either pinnate (divided to the midrib) 

 or united, and even anastomosing (intermixed). 



