FEJ^XS. 247 



of the older fronds bearing the sori, I should think that this plant requires 

 the growth of several successive years before producing them. The root- 

 stocks of many of the ferns I believe to be of considerable age, having 

 known the same plant year after year growing on the same spot. 



The vernation of Dkksonia is different from that of the Aspidiums, 

 the fronds being encased in sharply pointed buds, not rolled in the same 

 way, and covered by the brown chaffy scales that protect the hardy wood 

 ferns from the frosts of winter. 



Sensitive Fern — -Oak-leaved Fern — Onoclea seiisilnlis, (L). 



This fern abounds in low wet spots, marshy flats, and on the low- 

 lying banks of lakes and slow-flowing streams, where there is shade 

 and the soil is suitable ; it grows to the height of three feet and 

 upwards ; much dei)ends upon the age and strength of the thick, black 

 root-stock, which extends horizontally, sending up stiff upright stipes, 

 and large triangular fronds, which vary considerably at different periods 

 of growth, and are circinate or ■ rolled when they issue from the bud ; 

 being at an early stage, covered with fine white velvety down, which 

 afterwards disappears. 



The seedlings of the Oak-leaved Fern, Onoclea sensibilis differ 

 with succeeding years ; at first a tiny, delicate, little club-shaped, three- 

 lobed plant, semi-transparent of a very light-green colour ; the next 

 year it has made a great start in size and darkness of colour. We next 

 find it a strong vigorous fern with the divisions of the frond, long, waved at 

 the margin, and having veinings distinctly marked ; rhizome, thickened, 

 extending under the surface with strong, black, wiry roots and buds ready 

 for the next year's growth ; for the next few years the leafy fronds increase 

 in size and substance, but still make no attempt at forming fertile fronds. 

 When full grown it is no longer like the original seedling that we 

 noticed among the damp, spongy, peat soil of the low swampy river 

 bank; but a large robust plant spreading abroad its coarse, wide-expanded 

 frond. After a time, from the crown of the rhizome rise some shorter 

 fronds, having smooth stipes, and instead of being foliaceous the pinnules 

 are short, rolled up and converted into berry-like involucres, forming a 

 one-sided panicle. 



The sori are round and borne on the back of the veins, and are 

 quite concealed within the berry-like involucres. 



Later in the season the normal fertile fronds turn dark-brown, and 

 remain persistent till the following year. 



The age of the root-stock of this fern appears very considerable^ 

 indeed we know not how long it endures, sending up by extension new 



