WILSON'S FILMY FERN. 59 



WILSON'S FILMY FERN. 



HTMENOPHTLLUM WILSONI. 



[Hooker and Eabington.] 



(Fig. 33.) 



SYNONYM. 



HYMENOPHYLLUM UNILATEEALE. Wildenow, Moore, 

 and Newman. 



THIS plant is regarded as a distinct species by some 

 writers, although it differs so slightly from Hymeno- 

 phyllurn tunbridgense that we can hardly consider it 

 as such. It is found in the same districts, and often 

 accompanies it. Perhaps, however, the variety is 

 the more common in Scotland and in Ireland than the 

 original fern. The principal characters of distinction 

 are found in the fructification. The cups or seed- 

 vessels are larger, the valves more rounded, meeting 

 by their edges, not compressed toward the apex, and 

 never serrated. The darker green hue and coarser 

 texture of the plant will generally enable the collector 

 to distinguish this variety. The pinnae also are turned 

 back in a direction contrary to the fructification. 



Mr. Newman gives ample directions for the culti- 

 vation of this fern and the preceding species, and 

 suggests that it be grown on the surface of an inverted 



