216 
HISTORY OF BRITISH FERNS. 
fertile stems to the claw of some animal, as of the wolf. 
Hence one species, and that which probably suggested the 
name, has been called Wolfs-claw. 
Lycopodium Selago, Linnceus. 
Fir Cluh-moss, (Plate XX. fig. 5.) 
The Fir Club- moss is one of our commoner and stouter 
kinds. It is usually of upright growth, the others being 
decumbent ; though of this there is a variety, or mountain 
form, sometimes met with,, in which the stems are con- 
stantly prostrate. Indeed, in the commoner forms the 
upright habit, which is evidently natural to it, often gives 
way before the force of gravity, and in such cases the 
lower part of the stems is found to be somewhat recum- 
bent, while the upper parts retain their upright position. 
The stems vary from three or four to six or eight inches 
high, and are branched two or three times in a two-forked 
manner ; they are stout, tough, rigid, nearly level-topped, 
and thickly clothed with imbricated leaves arranged in 
eight rows. These leaves are lance-shaped and acute, of a 
shining green, rigid and leathery in texture, and smooth 
on the margin ; in plants which have grown in exposed 
places, they are shorter and more closely pressed to the 
