POL YPODIA CE^. lOS 



at base, often auricled, the lower much reduced ; texture sub^ 

 coriaceous; veins flabellate; sori i — 2, linear-oblong, parallel 

 with lower edge of pinnee. Huachuca Mountains, Arizona. 

 1 1 Rachis green. 

 9. A. viride Huds. Stipes densely tufted, 2' — 4' long, 

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

 broad, with 12 — 20 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. 



10. A. dentatum L. Stipes tufted, • 2' — d long, naked, 

 ebeneous below; fertile fronds 2' — 3' long, i' broad, with 6 — 8 

 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. 



tt PinruE only 2 — 5, linear-cuneate. 



11. 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 

 {Bigelow) ; Middle Mountains, Colorado, Arizona. 



tft PimKE numerous, linear or linear -oblong, acute or acuminate. 



Od- 12. A. angustifolium Michx. Stipes 1° or more long, 

 brownish, slightly scaly below; fronds 1^°— 2° long, 4'— 6' 

 broad, lanceolate-oblong, flaccid ; pinnae 20—30 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. 



( 13. 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 



