204 HISTORY OF BRITISH FERNS. 



Genus XVIII. BOTRTCHIUM, or MOONWORT. 



This small and very distinct plant is easily known by 

 two circumstances, — first, it has two fronds or rather two 

 branches of its frond, the one of which is leafy, the other 

 seed-bearing ; and secondly, the pinnae of the leafy branch 

 are crescent-shaped, with the outer margin jagged. There 

 is no other native plant which has these peculiar features, 

 and hence the Moonwort is a plant very easily recognized 

 when it is met with. It is rather local in its range, but 

 not scarce in the localities where it is found, which are 

 open heaths and pastures, rather dry than otherwise. The 

 spore-cases are collected into branched clusters at the end 

 of the fertile branch ; the little branches of the cluster 

 are all turned one way, and the spore-cases themselves 

 are numerous and globular, and somewhat resemble in the 

 aggregate a miniature erect bunch of grapes. 



There is another peculiarity in this Fern which also 

 serves to distinguish it, and its near ally the Ophioglossum, 

 from all other native species — the venation is straight, not 

 circinate ; that is, the fronds, before they are developed, 



