INTRODUCTION. 
3 
LYCOPODIALES. 
Leaves never in whorls, the blade moderately developed and never much 
divided. The thecae axillary and sessile, or in stalked capsules. Spores of two kinds. 
Tliecaj indehiscent, inclosed within the base of radical 
leaves. Leaves hollow and filiform. Stem a corm or 
solid bulb. Vernation straight. ( Water plants.) 
Thecae axillary, on a leafy spike or stem, two to four 
valved, sessile, free, dehiscent by a regular fissure. Stem 
solid, clothed with small overlapping leaves, creeping or 
upright. 
Thecae in coriaceous, stalked capsules near the base of 
radical leaves. Leaves ( Pilularia ) filiform. Stem long 
and creeping. Vernation circulate. 
Isoetace.e. 
>Lycopodiackas. 
Marsileace.e. 
POLYPODIACEiE. 
( Including Grammitis, Polypodium , Woodsia, Cystopteris, Aspidium, Asplenium, 
Scolopendrium, Blechnum, Pteris, Cryptoyramma, Adiantum.) 
Polypodiaceas, Hr., D.C., Kaulf., Bory, Hook., Grev., Mack., 8fc. 
Filices Ver.e, Willd., Linn., Schreb., Juss. 
Filices Annulate, Hoffm. 
Filices Gy it at as, Web., Mohr, Swtz. 
Filices Dorsifeiwe, Smith. 
Filicales, Lindl. 
Pteridales, Filicales Phy^llopterides, Epiphyllospermeas, &c. &c. 
STRUCTURE.* — A Fern consists of stem, roots, leaves, and fructification. 
The rootstocks or subterranean stems, as weU as the fibrils or true roots, are 
vulgarly included under the term root ; while the word frond is often applied to 
the leaves, which generally constitute the only part above the ground, except the 
fruit and its appendages ; the leaf is subdivided into rachis or petiole, or leaf- 
stalk, and pinnae or leaflets, which latter are generally more or less compound, 
lobed, indented or divided into pinnules. 
The Rootstock of all our native Ferns is perennial and fibrous. The' fibres 
are stout, generally hairy or scaly. In many cases the fibres issue from a crown, 
and form a tuft of roots : in others, from thick stems, which in the British species 
creep under ground, sometimes to a considerable distance. These rootstocks, 
rhizomes, or creeping stems are furnished with buds, irregularly disposed upon 
their surface ; the uppermost ones yielding leaves, while those below produce 
radical fibres. 
The Rachis or Leaf-stalk is sometimes smooth, at others scaly or hairy, some- 
times whoRy clothed with leaf-like expansions ; at others void of them at the 
* In illustration of the structure of all the tribes, the reader is referred to the illustrations 
of genera and their explanation. The stomata afterwards spoken of may very easily be seen in 
any under part of the epidermis, merely by tearing it off and submitting it to the microscope. 
The arrangement of the vessels in the stalk is apparent to the unassisted eye in any transverse 
section of it; and to view the spiral vessels it is only necessary to take two pins, and having 
thrust them through one of the bundles of vessels, separate them a little from each other, 
and in the cleft thus made the spirals will appear distinct when considerably magnified. 
