
THE COMMON ADDER'S TONGUE. 337 
like manner, and produce a new crown at a distance from the 
parent, in which manner the plants are multiplied. The rudimentary 
plant of the perennial crown instead of being as in the Moonwort 
enclosed within the stem, forms a new growing point by its side. 
Vernation plicate or folded straight, the sterile branch enclosing 
the spike of fructification. 
Stipes erect, smooth, cylindrical, hollow, succulent, usually elon- 
gated to about two-thirds the height of the frond, traversed by two 
‘or three vascular bundles, the base enclosed by membranaceous 
sheathing scales; divided above into a separate fertile and barren 
branch. 
Fronds from three or four inches to a foot in height, thin but 
somewhat fleshy in texture. Sterile branch smooth, entire, sessile, 
` broadly-ovate or ovate-elongate, acutish or obtuse, pale yellowish- 
green. Fertile branch erect, consisting of a simple spike terminating 
a more or less elongated footstalk, which appears to spring from the 
inner base of the sterile branch ; spike linear, very slightly tapering 
upwards. It occasionally happens that fronds are met with deve- 
loping from two to six fertile spikes, but it is very seldom that more 
than one frond is produced from each crown. 
Venation of the barren branch consisting of a series of uniform 
veins (no costa or midvein) everywhere anastomosing, and forming a 
series of narrow elongated hexagonal areoles, those towards the 
circumference becoming shorter and broader; within these are a 
series of lesser veins (venules) dividing the areoles into other smaller 
ones of similar form; and from the sides of these again branch, 
more or less abundantly, short divaricate free included veinlets, which 
are usually more numerous near the margin. 
Fructification occupying the margins of the linear spike, which 
terminates the contracted fertile branch. Spore-cases smooth, 
spherical, without ring or reticulations, embedded in a single series 
along the two opposite edges of the spike, bursting transversely, and 
then forming gaping concavities which give a toothed appearance to 
the margins. Spores verruculate, roundish, pale-coloured. 
` Duration. The crowns and roots are perennial. The fronds are 
annual, growing up in May, reaching maturity in June or July, and 
then gradually drying up and perishing. 
VOL. II. 

