SPINULOSE, OR COMMON WOOD-FERN. 



275. — Lastrea dilatata. Presl, Tent. Pterid., p. 77, — Moore, Nat. Pr, 

 Brit. Ferns, t. xxii — xxvi. — Dryopteris dilatata, Gray, Manual, ed. 1., p. 

 531. — Aspidium campylopterum, Kunze, in Silliman's Journal, July, 

 1848, p. 84. 



Hab. — In shady woods, often in springy places and along shaded 

 rivulets, from Newfoundland to Oregon and North- West America, and 

 extending southward to North Carolina, Tennessee and Arkansas. The 

 typical form, our var. vulgare, has been seen in Newfoundland, New 

 Brunswick, Canada, New England, the Middle States, Kentucky, about 

 Lake Superior, and westward to British Columbia. Var. intermedium 

 has nearly the same range, but extends to Tennessee and probably to 

 Arkansas, and is not reported from Newfoundland. It is the common 

 form of the species in the northern United States. Var. dilatatum is 

 found on the higher mountains of New England, and extends along 

 the Appalachian chain to North Carolina : it is known in Newfoundland, 

 New Brunswick, Canada, and thence westward to Oregon, British Co- 

 lumbia and Alaska. In New England and New York it seems to pass 

 in less mountainous districts into both the other forms. Aspidium 

 spinulosum, in several forms, is common in Europe and northern Asia, 

 and is credited to the Cape of Good Hope also. Var. intermedium 

 seems to be exclusively North American. 



Description: — The root-stock is either creeping or as- 

 surgent, or even occasionally erect. It may sometimes be 

 found six or eight inches long, but is usually much shorter. 

 It has an actual diameter of about a quarter of an inch, but as 

 the fleshy bases of the stalk are adherent and continuous with 

 it, and persist unwithered for at least a year after the fronds 

 have gone, the thickness of the whole is considerably greater. 



