206 
HISTORY OF BRITISH FERNS. 
base of which is invested by a browii 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 pinnae are crescent-shaped, or 
somewhat fan-shaped approaching to lunate, filled with a 
radiating 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 pinnae 
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 Moonwort is not very easily cultivated. ^ It may, 
however, be preserved in pots in a cold frame, if trans- 
