FERNS. 



227 



particularly that of limestone rocks. In the mountains of British 

 Columbia and Quebec the rare Pelhca densa is found. 



The first of these beautiful ferns, P. gracilis may be found on the 

 western bank of the Otonabee, close to the village of Lakefield, North 

 Douro ; its short, tufted, wiry, roots, closely wedged within the crevices- 

 of the limestone, from which it is difficult to dislodge them, without 

 destroying the delicate foliage of the plant. 



The chief nourishment of the plant must be derived from the moist 

 atmosphere in which it grows ; watered by the ascending spray and 

 mist, from the fast flowing river below the rocks where it makes its 

 home. 



This species of Rock-Brake is the smallest and most fragile of all our 

 native ferns. Graceful in outline and almost semi-transparent in 

 texture, of a light and tender green colour, it may be seen by a close- 

 observer, early in the month of June, clothing the otherwise barren 

 surface of the rocky wall that bounds the river in front of Strickland's 

 saw-mill, and enlivening it with its delicate verdant tufts of foliage. 



The fertile frond is somewhat duller and sadder in colour, and 

 stands upright above the drooping sterile fronds. The tallest of these 

 upright fruitful fronds rarely exceeds nine inches, oftener from four to- 

 six. The yellow, creeping and tufted root-stock throws out a vast 

 number of fronds. The thread-like stipe of the sterile fronds is so lax 

 that it is scarcely able to support the thin leafy frond and thus causes 

 its drooping habit. The fruit-bearing frond is more substantial, the 

 pinn?e, irregularly, bi-pinnatifid, from five to six or seven pairs, the upper 

 pinnule longer than the two lateral ones, blunt, and bearing the sori 

 in a marginal row, terminating the tips of the forked veins, the margin of 

 the pinnules forming a protecting indusium, at first white, then turning^ 

 to a very light-brown. The seed seems to come to perfection early 

 in July. In August the plant withers with the continued Summer heat, 

 sheds its fine yellow dust-like spores and dies away. 



This very lovely little fern is rare in this part of the country. I 

 have only found it in one locality, but it appears, not unfrequently, on the 

 banks of the rapid Moira, above Belleville, at Ottawa and Quebec, and 

 probably in other similar localities. Truly it well deserves its specific 

 name gracilis from its drooping fragile nature and slender habit. 



Cliff Brake — Pelhca afropiirpnrea, (Link.) 



Like the former this fern grows in rocky soil. The specimens 

 that I saw came from the vicinity of Hamilton, and also from the rocks 

 below Niagara Falls. The largest of these specimens did not exceed nine 

 inches, the smallest four inches. 



