49G FEUN FAMILY. 



lower pair turned obliiiuely forwards ; secondary divisions crowded, ob- 

 lon,:;, obtuse, entire ; fruit dots all near tiie margin. 



P. hexagon6ptera, Fee. Coninion N. and S. ; larger than the last, 

 which it uuu'li resembles, bat the frond is broader tlian long; lowest 

 ])innie much the largest and with elongated and pinnatitid divisions ; fruit 

 dots not exclusively near the margin. 



* * Fronds icith three primary diviKiuns, ichich are stalked; rhachis icing- 

 less. 



P. Drydpteris, Fee. Common X. ; fronds broadly triangular, 4'-(3' 

 wide, smooth ; the three primary divisions triangular, once or twice pin- 

 nate with oblong, obtuse, entire, or toothed lobes ; fruit dots near the 



16. ASPIDIUM, SHIELD FERN. (Greek for a littlp shield, refer- 

 ring to the indusium.) A very large genus, inhabiting all parts of the 

 world. (Lessons, Figs. 502-504.) 



§ L NEPHR6DirM or Dryopteris. Indnsium roniid-kidney-shaped or 

 nearly circidar, wiLh a narrow cleft from the loicer side almost to the 

 center. 



* Fronds thin, decaying in early autumn (or tender hot house plants), 

 pinnate ; pinnoi simply pinnatifid, with mostly entire, obtuse lobes; in- 

 dusium small. 



•*- Bootstock creeping, slender, nearly naked, and bearing scattered fronds ; 

 veins free, simple, or once forked ; common in bogs and low grounds. 



A. Tlielypteria, Swartz. Fronds lanceolate, 10'-18' long, on .slender 

 stalks, nearly smooth ; pinnte lanceolate, 2'-4' long, about ¥ wide, 

 spreading or turned down, the lowest pair scarcely shorter; divisions ob- 

 long, fruiting ones seeming acute from tlie revnlute margins ; veins mostly 

 forked ; fruit dots confluent wiien ripe ; indusium smooth ; N. and S. 



A. Noveboracense, Swartz. ]\Iuch like the last, btxt hairy beneath 

 along the riiachis and veins ; fronds tapering both ways from the nnddle ; 

 lower pinnae gradually smaller and distant ; lobes flat, the basal ones 

 often larger and incised ; veins rarely forked ; fruit dots distinct ; indu- 

 sium sliglitly glandular. N. (^ar., N. and W. ; common N. 



-I- -t- Bootstock oJdique or erect, stouter, bearing the fronds in a crown ; 

 veins simple, free, or the lower ones of contiguous lobes united; indu- 

 sium hairy. 



A. patens, Swartz. Low, shady grounds, Fla. and W. ; fronds l°-2° 

 high, sparsely pubescent, ovate-oblong ; pinnse 3'-0' long, i' wide, numer- 

 ous, lanceolate from a broad base, lowest pairs a little smaller ; divisions 

 oblong, slightly falcate, obtuse, or acutish ; veins entirely free ; indusium 

 slightly hairy. 



* * Fronds smooth, from once to thrice pinnate, growing in a croicn from 

 a stout and chaffy rootslock, and often remaining green through the 

 vnnter ; veins 'l-^-forked or branching. Wild species of the country. 



■*- Fronds imperfectly evergreen, once-pinnate with deeply pinnatifid 

 pinme, or nearly twice pinnate; fruit dots not close to the margin; in- 

 dusiuju rather large, flat, smooth, persistent. 



A. Goldianum, Hook. Rich, moist woods. Conn., to Ky., and N. ; 

 fronds broadly ovate, 2°-4° high, 9'-12' wide ; pinn;e oblong-lanceolate, 

 broadest about the middle, parted to the midrib ; divisions very numer- 

 ous, nearly 1' long, somewhat scythe-shaped, rather acute, serrate with 

 incurved teeth ; fruit dots very near the midvein. 



