192 
BRITISH FERNS. 
The Common Moonwort is furnished with stout 
succulent roots; as in the Adder’s-tongue the caudex 
and stem are one, and the base 
is enveloped in a brown sheath. 
In the centre of the swollen 
base another sheath is con- 
tained, and within it the young 
plant for next year, perfect in 
every part ; within the base of 
this is a still more minute 
embryo, that of the second 
year’s plant! The stem shoots 
up an inch or two above the 
ground, and then the frond 
diverges obliquely from it, its 
two rows of crescent-shaped 
leaflets tinged with a purplish- 
green horse-shoe mark in the 
centre. The leaflets are of a full green, leathery in 
texture, and placed opposite one another. The stem, 
continuing upwards in a perpendicular direction, is 
crowned by the compound spike, greenish in youth, pale 
chestnut in maturity, the capsules all turned one way. 
Mr. Cruikshanks found a curious variety of this fern 
growing on the sands of Barry, near Dundee. It had 
large roots without branches, and very succulent. The 
stem was branched near the summit, the barren branch 
was pinnate and triangular, the pinnse long and narrow 
pinnatifid, the leaflets cut into two or three lobes. The 
whole of the barren branch resembled a leaf of Tha- 
lictrum , hence the plant was called Rue-leaved, Botry - 
chiimi rutaceum . Sir William Hooker does not include 
this among his species, so it has either not been found 
