SPINULOSE, OR COMMON WOOD-FERN. 



than in var. vulgare, though there are fronds in which they 

 are only once pinnatifid. The secondary pinnae are usually 

 distinctly stalked, and are spreading like the primary ones. 

 The tertiary pinnae, or segments, are oblong-ovate, obtuse, and 

 spinulosely toothed on the sides and at the apex. The under 

 surface of the rachises and pinnules are minutely glandular 

 with unicellular cylindrical or capitate glands. The venation 

 is the same as in var. vulgare, and I see no difference in 

 the position of the sori, which are dorsal if on the veins, or 

 either dorsal or sub-apical if they are formed on branches of 

 the veins. The indusium is sprinkled on the surface and at 

 the margin with stalked and sessile glands. 



Mr. Davenport has endeavored to elevate this variety to 

 the rank of a species, under the name of Aspidium Ameri- 

 canum, rejecting the name of intermedium because Willdenow's 

 description "does not contain a word in regard to the gland- 

 ular indusiums and under surface, while, on the other hand, 

 his description of A. spinulosum does, thus exactly reversing 

 the usual arrangement." To the first objection it may be 

 replied that neither does Willdenow speak of. the glandular 

 lower surface and indusia of A. rigidum, where the glands 

 are much more conspicuous ; to the second that A. spinulosum 

 is often glandular in European specimens. Willdenow had 

 no American examples of the true spinulosum. Milde, who 

 had examined the specimens of intermedium sent by Muhlen- 

 berg to Willdenow, says it is " nothing but a common form of 

 A. spinulosum!' But our intermedium he refers to his 



