ORDEuCLX. 



ORDER ICO. FILICES. 



FERNS. 



815 



Stem a perennial, creeping, horizontal 

 rhizome, or sometimes erect and arbores- 

 cent. Fronds -(fruit-bearing leaves) va- 

 riously divided, rarely entire, with forked 

 veins, and mostly circinate vernation. 

 Fructification occupying the back or mar- 

 gin of the fronds, arising from the veins. 

 Sporangia (spore-cases) of one kind, scat- 

 tered or clustered in sori, 1 -celled, con- 

 taining numerous, minute spores. An- 

 theridia and pistillidia formed after ger- 

 mination, on the young plant. (See figs. 

 491501.) 



Genera 200, fpecie* 2000. A larce and in- 

 teresting order of flowerless plants, distin- 

 guished for tlieir elegant, plume-like foliage. 

 They are usually a few inches to a few feet 

 fiigli, but sonic of the tropical species, as the 

 Cy:itheip of both Indies, are 1525 feet high, 

 Vicing with the palms in si^e and beauty. 



Properties. Generally mucilaginous nnd 

 mildly astrinsent, henco considered pectoral. 

 Asjiidium and Pteris are anthelmintic. Os- 

 inv.nda regalis has been successfully adminis- 

 tered for the rickets. 



ObK6r*vfition,-^- r rhe fructification of the fern^, 

 with its various appendages, is too minute to 

 be well observed by the naked eye; but an 

 irxamination of it With the aid of a good lens 

 cannot fail to be interesting and satisfactory. 



739 p<,lypodmin vr.lgare. 710 Frond. 

 Lobe of tiio. frond enlarged, showing tho sori. 

 742 O no <if tho sori enlarged, showing the ?[>or- 

 angin. 743 One sporange further inagnilied, 

 bursting ami discharging the spores. 744 S or 113 

 of Aspidium marginalc/covered with the imla- 

 sitim. 745 Same, side view. 



SUBORDERS AND GENERA. 



Frond car.linc, solitary, straight in vernation. Stem erect. (_) 



% Fronds cauline, several, palmate (or radical and filiform), (b) 



Fronds all radical* clustered (never filiform), circinato in vernation. (2) 



2 Sporangia spiked or panicled, naked (not involved in revolute fronds). (!:) 



2 Sporangia on tho back of the fronds, but involved in the revolute segui Nos. S, tfl 



not involved ; segments flat, (c) 

 SriioKDER I. OPHIOGLOSSEJ3. (Sporangia naked, smooth, cartilaginous, 2-valved ; no ring.) 



a Fructification spicate. Frond entire, reticulate-veined OPIHOGLOSSUM. 1 



a Fructification paniculate. Frond divided, fork-veined BOTETCHIUI* 2 



.I-!JOKDEK II. OSMUNDEJi (Sporangia reticulate-roughened, papery, 2-valved, 



with no ring, epicatc or paniculate.) b Fronds palmate. Climbing LYGODICM. 3 



b Fronds filiform. Erect., , SCHIZ^K. 4 



b Fronds 1 2-pinnate .OSMITXKA. 5 



BUBORDEB III. POLYPODINE.E. (Sporangia minute, on the back of the frond, 

 valvelcss, torn open by the elastic ring which encircles it vertically.) 



C Sporangia scattered singly all over the surface (not in sori), naked ACROSTICTU. v 



C Sporangia collected in dots (sori) springing from the Veins, (c) 

 d Fruit-dots naked, having no indusium (special covering), (c) 



O Fronds all alike, fiat. Fruit-dots orbicular roi.vroiMtr.M. T 



6 Fronds sterile and fertile very different ; the fertile spike-liko STBUTIHOPTERIS. t> 



d Fruit-dots invested with special coverings (indi-.sia). (g) 



g Fruit-dots marginal ; indusium a narrow, reflected edge of frond, (h) 



h Indusium continuous all around the segment PTERIB. !) 



h. Indusium from the apex of the segm. Midvein central. CIIEILANTHES. 10 



1 Midvein lateral or AniAvrr.M. 11 



h Indusium ti reflected tooth at the sinus between the segments DICKSOMA. 13 



