THE RIGID BUCKLER FERN. 



Lastrea rigida. PRESL. 



This Fern is of moderate size, growing from a foot to 

 two feet in height, erect, and spreading, the fronds 

 annual, springing from the crown of a comparatively 

 thick scaly tufted stem, or caudex. It is one of the 

 most elegantly divided of the Lastreas, the pinnules 

 being all doubly and very evenly serrated, or toothed. 

 The fronds are narrowly triangular, rarely somewhat 

 lanceolate, bipinnate, with narrow tapering pinnu> ; 

 comparatively small, and generally broadest at the 

 base, always covered with minute glands, giving off a 

 pleasant balsamic fragrance when bruised, to be smelt 

 also in the sunshine from the untouched plants. The 

 outline of the pinnules, bluntly oblong with shallow 

 lobes (differing in this from the other native species of 

 the genus), is most nearly approached by some forms 

 of Filix-mas incisa, and the serratures also, as in that, 

 are not at all spinulose or bearded, but short and 

 merely acute (it is, however, distinguishable from that 

 by its size, its outline, its glandular surface, and its 

 glandular-fringed indusium). It can hardly be mis- 

 taken for any other of the Lastreas, nearly all the rest 

 of them having spinulose serratures. 



