152 ACOTYLEDONS. CILICES. Grammitis. 



HAB. Subalpine situations. Common in the ravines of Lorn, Capl. 

 Carmichael. 



22. Br. marginatum, stems elongated, leaves ovate acute reti- 

 culated their margins thickened serrated, nerve reaching a 

 little beyond the point, capsule ovate pendulous, lid shortly 

 rostrate. Muse. Brit. p. 126. t. 31. 



HAB. Moist and wet places among rocks. 



23. Br. hornum, stems elongated, leaves lanceolate acute reti- 

 culated, their margins thickened denticulate, nerve generally 

 disappearing below the summit, capsule oblongo-ovate pendu- 

 lous, lid hemisphaerical mucronulate. Muse. Brit. p. 127. /.31. 

 Mnium hornum, Lightf. p. / 11. 



HAB. Marshes. 



24. Br. cuspidatum, stems elongated, leaves obovate acute re- 

 ticulated their margins thickened denticulated above, nerve 

 running beyond the point, capsule ovate pendulous, lid coni- 

 co-hemisphaerical obtuse. Muse , Brit. p. 127. t. 31. Mnium 

 serpyllifolium y., Lightf. p. 715. 



HAB. Moist shady woods, plentiful. 



ORDER VII. FILICES. Br. M'irb. 



Fructifications only of one kind on the same individual. Cap- 

 sules spiked or racemed, or mostly collected into clusters of 

 various shapes (sori) upon the back of the leaf or frond, na- 

 ked or covered with an involucrum, often surrounded by an 

 elastic ring and opening irregularly, or without a ring and 

 opening with a regular jissure. Seeds or sporules minute. 



There is, usually, a subterraneous horizontal stem or cau- 

 dex. Fronds, before expansion, circinate; they are simple 

 and entire, or variously divided and branched, and cut into 

 lobes and segments, or leaflets of various forms. Substance 

 varying from membranaceous to coriaceous. In the tropics 

 the caudex forms a trunk resembling that of the palms. In 

 their internal organization the Ferns (as well as probably the 

 three following orders) differ remarkably from the rest of the 

 Acotyledons ; for they have, besides the cellular structure, lon- 

 gitudinal tubes or vessels, as we see in the monocotyledonous 

 stems, and these frequently placed in bundles. 



Div, I. GYRATVE, Br. (Polypodiacece). Capsules \-celled, fur- 

 nished with an articulated, elastic, longitudinal (generally in- 

 complete) ring, transversely and irregularly opening. 



1. GRAMMITIS. 

 Sori oblong, sublinear, straight, scattered. Involucre none. 



