114 OUR NATIVE FERNS AND THEIR ALLIES. 



each segment ; indusium slightly glandular or glabrous. (Poly- 

 podium thelypteris L.) New Brunswick to Manitoba south to 

 Texas and Florida. 



\\ Veins simple. 



i2a. D. simulata Dav. Rootstock slender, brownish ; fronds 

 S'_ 20' long, 2' 7' wide, oblong-lanceolate, tapering to an 

 acuminate apex; pinnae 12 20 pairs, lanceolate, the segments 

 obtuse, entire, slightly revolute in the fertile frond, finely 

 pubescent, especially near the midribs; sori rather large, some- 

 what distant, 4 10 to each segment; indusia finely glandular 

 at the margins. New Hampshire, Massachusetts. 



13. D. patens (Swz.) Ktze. Rootstock stout, bearing sev- 

 eral fronds at the growing end ; fronds 2 3 long, 4' 10' 

 broad, ovate-oblong, softly pubescent beneath; pinnae closely 

 placed, linear-acuminate, lowest pair somewhat deflexed, all cut 

 three fourths of the way to the midrib; segments numerous, 

 acutish, basal ones longest ; veinlets evident, lowest ones of ad- 

 joining segments often uniting; sori near the margin; indusia 

 very pubescent. (A. molle Kunze.) Florida to California. 



** Texture firmer or sub-coriaceous, veins forking freely . 

 t Fronds pinnate ; pinna cut into spreading triangular lobes ; 

 sori confluent. 



14. D. unita (L.) Ktze., var. glabra (Mett.) Unde. Stipes 

 i long, brownish, naked ; fronds i or more long, 5' 8' broad ; 

 pinnae narrow, cut from one third to half-way down into sharp, 

 pointed lobes; lower pinnae not reduced; veins pinnate in the 

 broad lobes with 6 8 veinlets on each side, the lower ones of 

 contiguous groups united ; sori near the ends of the veins prin- 

 cipally in the lobes. Florida. 



ft Fronds bipinnatifid or bipinnate ; indusia rather large ; 

 segments not spinulose. 



\ Fronds small, narrowly lanceolate. 



15. D. fragrans (L.) Schott. Fronds 4' 12' high, glandu- 

 lar-aromatic ; pinnae linear-oblong, pinnately parted; segments 

 toothed or nearly entire, nearly covered beneath with the very 

 large thin imbricate indusia, which are orbicular with a narrow 

 sinus, the margin ragged and sparingly glariduliferous, (Ne- 



