206 HISTORY OF BRITISH FERNS. 



base of which is invested by a brown membranous sheath, 

 which had covered it while in the bud. Above, the frond 

 is separated into two branches, one of which is spreading, 

 pinnate, leafy, oblong ; the pinnas are crescent-shaped, or 

 somewhat fan-shaped approaching to lunate, filled with a 

 radiatins: series of two or three times forked veins, such as 

 occur in Adiantum, one vein extending into each of the 

 crenatures into which the margin is divided. The other 

 branch is erect, fertile, compoundly branched, that is, it is 

 first divided into branches corresponding with the pinnae, 

 and these again into another series of branches, on which, 

 distinct, but clustered, the globose stalkless spore-cases are 

 produced. The spore-cases are two-valved, and open trans- 

 versely when ripe ; the valves are concave. 



Occasionally, though very rarely, two fertile branches 

 are produced, and there is a variety in which the pinnas 

 are pinnatifid. 



This species is widely distributed, but local, occurring 

 in open heaths and pasture, where the soil is peaty or 

 sandy, and not wet. The same plant occurs in other parts 

 of Europe, and also in North America. 



The IMoonwort is not very easily cultivated. It may, 

 however, be preserved in pots in a cold frame, if trans- 



