Order I
FILICES.
Of these the stem is perennial, often subterraneous and creeping, and occasionally becoming arborescent and leafy above the ground. The fronds or leaves are usually pinnatifid, and more or less compound; sometimes nearly simple and entire, with reticulated veins. The capsules are minute, one-celled, seldom manycelled, brown, membranous, and surrounded by a thick articulated elastic ring, irregularly bursting, and either clustered on the lower surface of the frond, or compound in spikes. Their vernation is circinate, and some are propagated by bulbs. The old botanists denied any fruit whatever to Ferns; believing the seeds of these plants to be so rare as to invest any body with invisibility who could collect them. Afterwards, their capsules were believed to be their seeds. Linnæus, and some others, doubted whether their fructification were seeds or pollen. Finally, the experiments of Ehrhart and Lindsay proved, beyond all cavil, that they were really seeds. As to the male organs nothing is known; some suppose them to be glands of the frond, others the elastic ring, some the indusium, and others the pores of the epidermis; lastly, Martius has supposed them to be the membrane including the spiral vessels. Ferns are chiefly inhabitants of the torrid zone, becoming rarer as we approach the poles. They delight in a humid soil, and they often grow parasitically upon trees. The medicinal virtues of some are highly astringent, of others anthelmintic, of others purgative; some have acquired celebrity for their pectoral, others for their corroborant qualities. The young leaves and roots of some constitute an article of food; beer is obtained from the roots of others, and, finally, Aspídium frágrans has been used as tea. 2168 Polybotrya H. & B. 2169 Acróstichum L. 2170 Hemionítis L. 2171 Gymnográmma Desv. 2172 Meníscium Schreb. 2173 Xiphópteris Kaulf. 2174 Céterach W. 2175 Polypódium L. 2176 Tæ'nitis Swz.
Tribe 1.
Tribe 1. POLYPODIACEE. 2177 Nothochlæ'na R. Br. 2178 Onocléa L. 2179 Struthiopteris W. 2180 Allosorus Bernh. 2181 Ellobocárpus Kaulf. 2182 Lomária W. 2183 Bléchnum L. 2184 Woodwárdia Sm. 2185 Doódia R. Br. 2186 Asplénium L. 2187 Allantódia R. Br. 2188 Scolopendrium Sm. 2189 Diplázium Swz. 2190 Ptéris L. 2191 Vittária Sm. 2192 Lonchitis L. 2193 Antrophyum Kaulf. 2194 Adiantum W.
Tribe 2. OSMUNDACEE. 2195 Cheilanthes Swz. 2196 Davállia Sm. 2197 Dicksónia L'Her. 2198 Balántium Kaulf 2199 Aspídium Swz. 2200 Woódsia R. Br. 2201 Cyathéa Sm. 2202 Trichómanes L. 2203 Hymenophyllum Sm. 2207 Anémia Swz. 2204 Tódea W. 2205 Osmúnda L. 2206 Lygódium Swz. 2208 Botrýchium Swz.
Tribe 3. OPHIOGLOSSEÆ. 2209 Ophioglóssum L. 2210 Maráttia Swz.