46 POLYPODIUM. 



lands of Scotland. Not very easy of cultiva- 

 tion, but growing plentifully where it does 

 take. A peculiarly elegant and graceful 

 plant (totally unlike any other of the 

 genus), overlooked in this country till 

 within the last very few years, in conse- 

 quence of its similarity to Asplenium Filix 

 Foemina. Var. Flexile, more distinct-look- 

 ing, pinnules more apart, narrower, less 

 frequently, but more deeply, sharply, and 

 widely, toothed. 



CALCAREUM. (Lime, or Rigid Three- 

 branched Polypody.) Fig. 39. From 6 to 

 12 inches. Growing in masses. Dusky 

 green. Frond stout, rigid, oblong-trian- 

 gular, concave ; the stem running into 

 three, as it were, at a bent angle and knot 

 in the lowest pinnae, which are horizontally 

 turned, and inclining upwards, the leader 

 forming its continuation. Pinnae oppo- 

 site, somewhat alternate above, and incom- 

 plete. Pinnules (or, as getting higher and 

 higher, simple pinnulets or mere scallops) 

 oblong, furrowed, deeply notched through- 

 out, and, in the larger, divided almost to 

 the midrib; having on the back small, 

 yellow, shining, glands, yielding, in the 

 young fronds, a pleasant but short-lived 

 perfume when drawn across the nose. In 

 the first stage, it appears like three tiny 



