FILICES. 105 



with lower edge of pinnae. Huachuca Mountains, Arizona 

 (Lemiiio)i). 



\\ Rachis green. 



3b - 8. A. viride Huds. Stipes densely tufted, 2' 4' long, 

 naked, the lower part chestnut-brown ; fronds 2' 6' long, f 

 broad, with 1220 pinnae on each side, which are ovate or 

 rhomboidal in outline, the upper edge narrowed suddenly at 

 the base, the lower obliquely truncate, the outer part deeply 

 crenate ; rachis naked ; sori copious. Vermont,. Canada, and 

 New Brunswick. 



9. A. dentatum L. Stipes tufted, 2' 6' long, naked, 

 ebeneous below; fertile fronds 2' 3' long, i' broad, with 68 

 pairs of stalked, oblong-rhomboidal pinnae, the lower side trun- 

 cate with a curve, the outer edge irregularly crenate ; sterile 

 fronds smaller on shorter stipes ; rachis naked ; sori copious in 

 parallel rows. Florida, South Carolina. 



ft Pinna only 2 5, linear -cuneate. 



10. A. septentrionale (L.) Hoffm. Stipes dense, tufted, 

 3' 6' long, slender, naked, ebeneous toward the base; fronds 

 irregularly forking, consisting of two to five narrowly linear 

 rather rigid segments, which are entire or more frequently cleft 

 at the end into a few long narrow teeth ; sori elongate, placed 

 near the margin, usually facing each other in pairs, commonly 

 only two or three to each segment. Ben Moore, New Mexico 

 (Bigelffw) ; Middle Mountains, Colorado, Arizona. 



ftt Pinna numerous, linear or linear-oblong, acute or acuminate. 

 n. A. angustifolium Michx. Stipes i or more long, 

 brownish, slightly scaly below ; fronds i^ 2 long, 4' 6' 

 broad, lanceolate-oblong, flaccid ; pinnae 2030 pairs, linear, 

 lanceolate, acuminate, entire or crenulate, those of the fertile 

 frond narrower; texture thinly herbaceous; sori linear, 20 40 

 each side of the midvein. New England to Kentucky and Wis- 

 consin. 



O- 12. A. firmum Kunze. Stipes 4' 8' long, erect, grayish, 

 naked; fronds 6 12' long, 3' 4' broad ; pinnae 12 20 pairs, 

 oblong-lanceolate, the point bluntish, the margin inciso-cre- 

 nate, the upper one narrowed suddenly at the base, the lower 



