POLYPODIACE^E. 



669 



Floral envelopes and sexual organs absent, or not discernible. Reproduced by minute 

 bodies called spores, usually enclosed in cases, theca or sporangia, or irregularly dis- 

 persed about the plant. Spores having no radicle, plumule, or cotyledon, germinating 

 indifferently in any direction, and striking root from any part of their surface. 



Class V.— Acrogens, or Acrogcnous Plants. 



Flowerless plants with a regular stem or axis growing from the apex, not increasing 

 in diameter; composed of cellular tissue and vessels, but sometimes of the former alone ; 

 usually furnished with leaves. Spores contained in a theca. 



Group LII. — Filicales. 



Order 120.— POLYPODIACE^.— Brown. 



Usually with a creeping rhizome ; sometimes with an erect, arborescent stem. The 

 leaves (fronds) circinate in venation, entire, or variously divided. Thecae arising from 

 the veins of the leaves, situated at their back or margins, often collected in clusters (sori), 

 either naked or covered with a transformed margin of the frond, or with a scale (indu- 

 sium). Thecce l-celled, containing innumerable spores; dehiscing irregularly, and some- 

 what different in the several sections of the order. 



Ferns are found in various parts of the world, but abound most in the tropi- 

 cal islands of both hemispheres. The tree ferns are found as high south as 

 46°, but have never been found further north than the tropic. Their leaves 

 and rhizomes usually contain a peculiar and astringent mucilage, which in 

 some species has a little aroma. Many of them have been used as medicinal 

 agents to fulfil several indications. 



Besides the Male Fern, the following species have been more or less em- 

 ployed. Several species of Adiantum, as the pedatum, 

 capillus-veneris, are considered as pectoral and de- 

 mulcent, and form the basis of the syrup called Capil- 

 laire, so much used in France and Germany in diseases 

 of the respiratory organs, and as a vehicle for the ad- 

 ministration of disagreeable remedies. Ainslie (Mat. 

 Ind. i. 52) states that a strong decoction of the latter of 

 these plants is decidedly emetic. A. fragile, of Ja- 

 maica, is said by Browne {JLunan. Hort. Jam. i. 475) 

 to be efficacious in phthisis and in an ulcerated and re- 

 laxed state of the glands of the throat. A. trapeziforme ■ 

 is used in the West Indies as a substitute for the A. 

 capillus-veneris. A. melanocaule (Ainslie, ii. 214) is 

 considered by Hindoo practitioners as having tonic powers. 



Some of the species of Polypodium appear to have more energetic powers. 

 P. vidgare, a native of Europe, as well as of this country, was anciently es- 

 teemed as a purgative in obstructions of the liver; and it was also supposed 

 useful in gout, colic, and even mania. It is likewise said to be expectorant 

 and diuretic. Though formerly universally employed, it is now seldom re- 

 sorted to ; yet from the results of analyses of it by Planche and others, it is 

 probable that it is possessed of some activity. The part used is the rhizome, 

 which, when fresh, is sweetish, but when dried is bitter. P. calaguala 



A. capillus-veneris. 



