SPINULOSE, OR COMMON WOOD-FERN. 



This plant is usually considered the type of the species ; 

 it is very common in Europe, less so in America.' It is well 

 represented on Plate xxi of Moore's Nature Printed British 

 Ferns, and on Plate i8 of Hooker's British Ferns. Being 

 obliged to give it some distinctive name as a variety, I have 

 selected what seems to be the oldest, that used by Koch, 

 who, however, placed the species in Polystichum. 



Var. intermedium has fronds a little broader in outline 

 than those of var. vulgare, and often larger; measuring not 

 unfrequently twenty-two inches long and nine inches broad 

 The color is dark-green. The pinnae diverge from the rachis 

 at an angle of from sixty to ninety degrees, being usually 

 more spreading than in the type of the species. The lowest 

 ones are sometimes nearly three inches distant from the next : 

 they are triangular-ovate in outline, and have the pinnules of 

 the lower side much longer than those on the upper side. 

 The first or basal pinnule is generally a little shorter than 

 the second one, a point noticed by Milde, but apparently 

 hitherto overlooked by American authors. Successive pinnae 

 are a little narrower and longer, the longest ones being com- 

 monly those just below the middle of the frond. The 

 secondary rachises are very narrowly winged. The pinnae are 

 usually fairly bipinnatifid, being one degree more compound 



I Milde has as sub-varieties, exaltatum, with dark-green glabrous fronds, elevatum, 

 with narrower yellowish-green and somewhat glandular fronds, and Amurense, with 

 broadly ovate fronds chaffy beneath with little bullate scales. He says that towards the 

 north of Europe the true sfirulosum becomes scarce and passes gradually into var. 

 dilatatum. 



