112 OUR NATIVE FERNS AND THEIR ALLIES. 



7. 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; pinnas closely 

 placed, linear-acuminate, lowest pair somewhat defiexed, 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 . 

 \ Fronds pinnate ; pinncB cut into spreading triangular lobes ; 

 sori confluent. 



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

 I J-° long, brownish, naked ; fronds i^° or more long, 5' — 8' broad ; 

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

 pointed lobes; lower pinnse 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. 



X Fronds small, narrowly lanceolate. 



9. D. f ragrans (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 glanduliferoijs. (Ne- 

 phrodium fragrans Rich.) New England, New York to Wis- 

 consin, and northward. 



\\ Fronds larger, mostly 2° — 4° high. 

 A. Fronds bipinnatifid or nearly twice pinnate ; indusia 

 large, thinnish and flat, 



10. D. Floridana (Hook.) Ktze. Stipes 6' — 10' long, spar- 

 ingly clothed with ovate scales; fronds lEinceoIate, 18' — 20' 

 long, 5' — 8' broad ; fertile pinnse confined to the upper half of 

 the frond, narrowly lanceolate, cut down to the narrowly 

 winged secondary rachises into oblong, distinct pinnules ; the 

 sterile pinnae broader, shorter, and sub-deltoid below, less 



