813 Oedbu 160.— FILIOES. 



Jn. (0. interrupta Mx.) As the sterile Ifts. unfold latest, early specimons ahoTf 

 the upper Ifts. fertile. Rarely the lowest Ifts. are all fertile. 



6. ACROS'TICHUM, L. Golden Fern. ■ (Gr. d/cpof, a point, (TT/;^;of, 

 a line or row ; from the fi-uit dots and lines.) Sporanges scattered (not 

 in sori), occupying tie under surface of the whole or a part of the frond. 

 — Fronds of %arious habit. 



A. aiireum L. Frond pinnate, piunte alternate, oblong-lanceolate, entire, equi- 

 lateral, cuneate at base, the upper bearing the fructification. — In deep swamps 

 near the sea coast, Fla. (Pursh). Cultivated occasionally in the greenhouse. It 

 is a noble Fern 3 to 5f high. Common in the W. Indies. 



7. POLYPO^DIUM, L. Polypod. (Gr. iroXvg, many, Troda, feet; 

 from the multitude of creeping rootstocks.) Sori roundish, scattered on 

 various parts of the under surface of the frond, with no indusium (cover . 

 or involucre). — Ferns of various habit. 



§ Makginaeia (simply piunate) reticulate-veined, clothed ■with scales No. 1 



§ PoL-vpODiu-M. Frond with the veins forked, distinct, — simply pinnate No. 1 



— hipinnatifid Kos. 8, 4 



— ternate, bipinnatifld No. 5 



1 P. iucanum Ph. Fronds deeply pinnatifld; segments alternate, hnoar, very 

 entire, obtuse, scaly beneath, the upper ones gradually smaller; stipe scaly, bear- 

 ing the fertUe segments near the apex; sori solitary and distinct. — A parasitic 

 fern, 3 — 6' high, growing on the inclined, moss-clad trunks of living trees, parti- 

 cularly of the huge Sycamore, and the Magnohas, in the damp forests along rivers, 

 W. States ! and also Southern. The scales resemble the indusia of other Ferns, 

 but have no fruit under tliem. The veins are invisible. 



2 P. vulg^re L. CoiiMOif Polypod. Frond deeply pinnatifld, smooth; segm. 

 Ihiear-obloDg, obtuse, cronulate, the upper ones gradually smaller ; sori large, 

 distinct. — Rather common on shady rocks and in woods, forming tangled patches 

 with their roots which are clothed with membranous scales. Fronds 6 to 12', 

 divided into alternate segments nearly to the midvein. Stipe naked and smooth. 

 Segments^parallcl, a little curved, about \' wide. Fruit in large, golden dots in a 

 double row, at lengtli brownish. July. (P. Virginianum "Willd.) 



3 P. Phegopteris L. Beeou Polypod. Frond bipinnatifid, triangular in out- 

 line, veins hairy, the lower pinnae deflexed but curving forward toward the apex; 

 saoments linear-oblong, obtuse, entire, ciliate, the lower adnate and decurrent; 

 stipe reirorsely pubescent, rachis chaffy. — Shady woods, Can. to "Wis. and N. States. 

 Frond longer thari wide (3 to G' by 2 J to C). Sori small, about 4 on each seg- 

 ment. July. 



4 P. hexagonopterum Mx. Trlingular Polypod. Frond bipinnatifid, ^mncs 

 rather distant, the lowest deflexed ; segments lanceolate, obtuse, chiate, crenate or 

 dentate, glandularly puberideni ieneath, the lowest decurrent apd forming a con- 

 spicuous wing to the rachis ; stipe smooth. — Moist open woods, U. S. eommun 

 South. Frond wide as long (5 to 8') triangular. Sori many on eacli segment. 

 Jl. (P. Phegopteris /?. cd. 2.) 



5 P. Dryopteris L. Ternate Polypod. Frond ternate, bipinnate ; branches 

 of the frond spreading, deflexed, segments obtuse, subcrenato; sori marginal; 

 root filiform, creeping. — This beautiful fern grows in shady places and mountain- 

 ous woods, common North. Root blacli and very slender. Stipe slender and 

 delicate, smooth, nearly a foot high, dividing into 3 light green, drooping, com- 

 pound leaflets of a very delicate texture. Jl 



/3. cALC.iREU5r. Branches of the frond erect, rather rigid. (P. calcareum Sm.) 



8. STRUTHIOP'TERIS, Willd. Ostrich Fern. (Gr. aTpovdog, an 

 ostrich, Tcreptc, a fcni.) Fertile fronds contracted, the margins rolled 

 backwards and covering the round, confluent sori, which are otherwise 

 without au indusium. — Fronds bipinnatifid, the fertile pinnse moniliform- 

 linear. 



