ORDER 159. FILICES. 417 



A large and interesting Order, distinguished for their elegant, plume- 

 like foliage. They are usually a few inches to a few feet high, but some 

 D/ the Tropical species, as the Cyathece, are 15 to 25 feet, vieing with the 

 Palms in size and beauty. 



53^~ The stipe is the stalk of the frond, and the rachis its continuation through it. The 

 i.inna (orpn.) are the first divisions of a divided frond (often called leaflets). Pinnula 

 (or pnl.) are the first divisions of the pinnae when further divided. Segments (seg.) are 

 \\iefinal divisions, and the partial divisions of the segments are lobes, &c. The sort (fruit- 

 dots) are either naked, or covered with an indusium (see cut), 

 g POLYPODIACE^E. THE TRUK FERNS, with fronds mostly radical, circinate in bud. Fporangia is 



sori, pedicellate, with a vertical, elastic ring, opening transversely... (/) 



g CYATHE ACE^E. THE THEE FERNS, with fronds on an erect trunk. Sporangia as in 1. . .(e) 

 HYMENOPHYLLACE/E. PELLUCID FKRNS ; sporangia in a cup and on a thread...(<fl 

 SCHIZ^ECEyE. Very slender vines or fronds. Sporangia with a ring-crown at apex... (c) 

 | OSMUNDI ACE^E. Fronds stout, radical. Sporangia with no ring, 2-valved. ..((>) 

 I OPHIOGLOSSACE.E. Frond single (in our species), on an erect stem. Sporangia with no ring. . .(a) 



a Fruit in a spike. Frond entire, reticulate-veined OPHIOGLOSSUH. 1 



a Fruit in a panicle. Frond divided, fork-veined BOTRYCHICM. 2 



b Fronds pinnate or bipinnate, with straight, forked veins OSMUND A. 3 



e Fronds palmately lobed. Stems climbing, 3 4f. LYGODIOM. 4 



c Fronds linear-filiform, undivided, a few inches high SCHIZ^EA. 5 



c Fronds 3-parted, middle division sterile, the lateral paniculate ANEIMIA. 6 



d Fronds pellucid or opaque. Sporangia with a transverse ring TRICHOMANKS. 7 



e Fruit-dots in little round cups. Trunk and leaves smooth CYATHKA. 8 



e Fruit-dots becoming entirely naked. Fronds prickly or hairy ALSOPHILA. 



Fruit-dots enclosed in the reflexed tip of the lobe, with two valves BALANTIUJT. 22 



/ Sporangia scattered singly all over the surface (not in sori), naked. . .(//) 

 / Sporangia collected in dots (sori) growing from the veins... (h) 



g Fronds simple or pinnate. Pinnae on short petiolules ACROSTICHDJC. 10 



it Fronds forked at the summit, entire below, the sterile different PLATYCERIUM. 1 1 



h Sori (fruit-dots) naked, having no covering of any kind...() 



h Sori involved (at first) in the rolled segments of the panicled fertile frond. . .(m) 



h Sori not involved, but iuvested with special coverings (called indusia) . . .(n) 



k Fronds smooth or scaly, never powdery. Sori distinct, roundish POLYPODIOM. 12 



k Fronds covered with powder on the back. Sori in many dorsal lines G Y.M XOGKAM M A. 13 



k Fronds powdery or scaly on the back (bipinnate). Sori in a marginal line NOTHOL.XNA. 14 



* Fronds linear, simple. Sori in a continuous line on the split margin. Fla VITTARIA lineata. 



m Fertile frond bipinnate, segments berry-like. Veins reticulated ONOCLEA. 15 



i Fertile frond pinnate, pinna; moniliform. Veins forking STRUTHIOPTERIS. 16 



m Fertile fronds bipinnate, segments oblong, soon opening ALLOSURUS. 17 



n Sori marginal, indusia only the reflexed altered margin of the frond. ..(o) 

 n Sori marginal, indusium double a scale combined with the margin... (p) 

 n Sori dorsal, oblong or linear, indusium attached to the side of a vein. ..(q) 

 tt Sori dorsal, round or roundish, indusium on the back or the tip of a vein. . .(x) 



o Fronds of 2 kinds, the fertile contracted. Sori continuous to apex LOMARIA. 18 



o Fronds all similar, smooth. Indusia continuous all around. Stipe green or brown.. PTERIS. 19 



o Fronds woolly, <tc. Sori separate or continuous. Stipe brown, hairy CHEILANTHES. 29 



o Fronds smooth. Sori separate. Stipe black and polished ADIANTUM. 21 



p Indusium a 2-lipped cup at the edge of the segments DICKSONIA. 22 



f Indusium an entire cup or goblet at the edge of the segments DAVALUA. 23 



q Sori parallel to the mid-vein, the indusia opening toward it.. .(/) 

 q Sori oblique to the mid- vein, borne laterally on the veinlets. . .() 



r Sori linear, nearly continuous, in 2 rows, sunk in the frond WOODWARDIA. 24 



r Sori oblong, remote, in two rows and superficial. Stipes black DOODI A. 26 



r Sori linear, in 1 double row, the whole length of the segment BLECHNUM. 26 



r 8ori oblong, in 1 short double central row. Frond finely clett ONYCIIIUM. 27 



s Indusia single, regularly arranged, in 2 rows ASPLKSIU.H. 28 



Indnsia single, scattered irregularly. Frond simple or lobed CAMPTOSORUS. 29 



Indusia double, regularly arranged. Frond simple SCOI.OPF.NPRIUX. '' 



