FiLicEs. (ferns.) G33 



very near the margin; indusium round-reniform, convex, thickish, smooth. — 

 Mountains of Georgia, and northward. — Fronds bhxish green, l°-2° long, on 

 a short stipe, which, like the short thick rootstock, is shaggy with large brown 

 chaffy scales. 



§ 2. PoLYSTicnuM, Roth, Schott. — Indusium orbicular, fixed by the depressed 



centre. 



10. A. acrostiehoides, Swartz. Fronds evergreen, thickish, smooth 

 and shining, lanceolate, the fertile ones tallest, pinnate ; pinnas numerous, 

 short-stalked, oblong-lanceolate, auriculate at the base on the upper side, cune- 

 ate at the lower, obtuse or acute, finely serrate or incised witli spinulose-pointed 

 teeth ; the upper pinuEe of the fertile frond contracted and covered with the 

 copious fruit-dots; indusium round, peltate, smooth and entire. — Shady and 

 rocky woods. — Fronds l°-2° high. Rootstock and stipe very chaffy. 



§3. Eu.\SPii>iUM, Uudw. — Indusium orbicular, peltate : veins reticulate. 



11. A. trifoliatum, Swartz. Frond thin, cordate-ovate in outline, 3- 

 lobed, or 3-foliate, the ovate pinnae entire or 3-lobed, acuminate, the margins 

 undulate ; sori scattered ; involucre peltate, orbicular. — Hernando County, 

 Florida ( Curtiss). — Frond l^ or less long, barely longer tliau the slender stipe. 



17. NEPHROLEPIS, Schott. 



Fruit-dots at the ends of the veins, in a series near the margin of the pinnae. 

 Indusium reniform, often broadly so, fixed by the sinus, or b3' the arcuate 

 base, open obliquely toward the margin of the pinuje. Fronds pinnate, elon- 

 gated ; tlie pinuaj articulated to the rachis. Veins free, forked from the mid- 

 rib, their apices tliickened. 



1. N. exaltata, Schott. Fronds linear, indefinitely elongated, unfolding 

 numerous pinme, which are oblong-lanceolate, auriculate on the upper side of 

 the base, rounded on the lower side, falcate, crenately serrate; fruit-dots 

 large; indusiuni reniform or crescent-shaped, the oblicjue sinus narrow and 

 deeper broad and shallow on the same pinnie. — South Florida. — Fronds 

 1° - 6° long, 2' - 3' wide, usually pendent from the trunks of trees. 



18. PHEGOPTERIS, Fee. 



Sori small, round, naked, borne on the back of the veins below the apex. 

 Stipe continuous with the rootstock. Veins free. 



1. P. hexagonoptera, Fe'e. Fronds annual, broadly triangular, bi- 

 pinnatifii] ; piuuai lanceolate, acuminate, spreading, the lower pair erect ; pin- 

 nules oblong, mostly obtuse, crenately toothed or entire ; fruit-dots numerous, 

 minute. — Shady woods. — A foot or more high from an elongated creeping 

 rootstock. PinuiB decurrent, forming irregular hexagonal wings on the rachis. 



2. P. polypodioides, Fee. Frond triangular-ovate; pinnre approxi- 

 mate, hairy, narrowly lanc(;(jlate ; fruit-dots marginal. (Polypodium Phegop- 

 teris, L.) — Mountains of North Carolina and Tennessee. — Stipe 6'- 9' long. 

 Frond A'-C/ broad. 



3. P. tetragona, D. C. Eaton. Frond erect, pubescent, 2'^ high, the 

 stipe sharply 4-angled ; pinnsse in di.stant pairs, neaidy sessile, lanceolate, acu- 



