Order 160,— 1TLICES. 



815 



Order CLX. FILICES. Ferns. 



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. 

 fYuctification 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, minuto spores. An- 

 theridia and iristillidia formed after ger- 

 mination, on tho young plant (See figs. 

 491—501.) 



Genera '200, specie* 24)00. — A largo and in- 

 teresting order of fluwerless plants, distin- 

 guished for their elegant, plume-like foliage. 

 They are usually a low inches to a few feet 

 bigh, but some of tho tropical species, as tho 

 Cyatheae of both Indies, arc 15 — '25 feet high, 

 Viuing with the palms in size and beauty. 



Properties. — Generally mucilaginous and 

 mildly astringent, hence considered pectoral. 

 Aspidium and Fteris arc anthelmintic. Os- 

 mu.nda regal is has been successfully adminis- 

 tered for the rickets. 



Observation. — The fructification of the ferns, 

 with its various appendages, is too minute to 

 be well observed by the naked eye ; but an 

 oxamination of it with the aid of a good lens 

 cannot fail to be interesting and satisfactory. 



'39 Polypodium vulgarc. 7U Frond. 741 

 Lobo of the frond enlarged, showing tho sori. 

 742 One of the sori enlarged, showing the spor- 

 angia. 743 One sporange further magnified, 

 bursting and discharging the spores. 744 Soma 

 of Aspidium marginalo covered with tho indu- 

 siutn. 745 Same, sido view. 



SUBOEDE11S AND GENEItA. 



§ Frond eniilinc, solitary, straight in vernation. Stem erect, (a) 



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



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



2 Sporangia spiked or panicled, naked {not involved in revoluto fronds), (b) 



2 Sporangia on tho back of the fronds, — but involved in tho revoluto segm Nos. 8, 10 



— not involved ; segments flat, (c) 

 3TTBocr>En I. OPIIIOGLOSSE.E. (Sporangia naked, smooth, cartilaginous, 2-valvcd ; no ring.) 



a Fructification spicate. Frond entire, reticulate-veined Opiiio-glosscxi. 1 



a Fructification paniculate. Frond divided, fork-veined BotryciiiUjS. 2 



Suborder II. OSMUNDE^E. (Sporangia reticulate-roughened, papery, 2-valved, 



with no ring, spicato or paniculate.) — b Fronds palmate. Climbing I.yoodium. 3 



• — b Fronds filiform. Erect Bernard 



— b Fronds 1— 2-pinnate Osmunda. 5 



Scborder III. POLYPODINE^E. (Sporangia minute, on the back of tho frond, 

 valvcless, torn open by the clastic ring which encircles it vertically.) 



C Sporangia scattered singly ail over tho surface (not in sori), naked Aorosticusi. ». 



C Sporangia collected in dots (sori) springing from the veins, (d) 

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



e Fronds all alike, flat. Fruit-dots orbicular Polyi'ooium. 7 



o Fronds sterile and fertile very different; the fertile spike-like STRtrrmopTEKia. 8 



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



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



h Indusium continuous all around the segment Ptrris. 9 



h. Indusium from the apex of tho segm. — Midvein central CnEiLANTHES. 10 



— Midvein lateral or AmAwrrnw. 1 1 



h Indusium a reflected tooth at the sinus between tho segments. . . .Dicksokia. 13 



