156 BRITISH FERNS. 
41. FORKED SPLEENWORT. Seprenrrronarz. 
Acrostichum septentrionale, Linneus. B.F. 265, 269. 
The radicles are very long, numerous, fibrous and 
interlaced, and, together with the caudex, which is 
large and tufted, often form an amazing bulk, when 
we consider the small size of the fronds. The fronds 
are very small, two or three inches long, and very 
narrow, scarcely more than a third of an inch in 
width; their form is elongate and almost linear, 
there being no perceptible division between the leafy 
part of the frond and its stalk, the leafy part 
' narrowing very gradually into the stalk, which is 
smooth and black at the extreme base; the sides 
_ of the frond have two or three bifid teeth on each 
side, and the tip is also generally bifid. The veins 
are nearly simple, and few in number, one running 
into each tooth; the seeds are attached to each vein 
in a continuous line, covered by a narrow white 
involucre, which opens towards the middle of the 
frond, and, as the seeds swell and advance towards 
maturity, this involucre is thrown backward, finally 
lost, and the undér side of the frond then presents 
@ continuous mass of brown seeds; the edge of the 
involucre is waved, but not jagged. This little fern 
