262 
HISTORY OF BRITISH FERNS. 
The side branches, which measure about four inches in 
length, are constantly branched at every joint with a whorl 
of branchlets averaging two inches in length, and some- 
times these branchlets put out another series of short 
branches. The outline would be nearly pyramidal, were it 
not that the extreme point becomes so slender as to be unable 
to retain itself erect ; the lateral branches are all drooping 
or deflexed, and hence the elegant appearance of the full- 
grown plants. The ultimate branches are three-ribbed, 
which gives them a triangular form ; their joints termi- 
nate in three long-pointed teeth, one of the ribs extending 
undivided to the apex of each tooth. The teeth are of the 
same colour as the branch. 
The section of the stem shows a series of shallow ridges 
and furrows ; opposite the latter a ring of largish cavities ; 
and alternating with these on the inner side, another ring 
of very minute cavities, these latter again alternating with 
a circle of angular cavities close to the inner margin of 
the tube. The central cavity measures about half the 
diameter. 
The fructification is an oblong-ovate cone-like head, 
consisting of eighty or more pale brown peltate scales 
ranged in whorls, and to which the white spore-cases 
