FILICES. (FERNS.) 629 



* * Fronds pinnatifid or simply pinnate. 



2. A. pinnatifidum, Nutt. Fronds lanceolate, acuminate, cordate at 

 the base, pinuatifid, or below sometimes pinnate, the roundish divisions ob- 

 tuse, crenate or serrate ; fruit-dots scattered. Alleghanies of Alabama, and 

 northward. Fronds 3' - 6' long. A form with the lowest segment on each 

 side elongated horizontally and acuminate has been found in Alabama by 

 Mr. Beaumont. 



3. A. dentatum, L. Fronds linear-oblong, obtuse, pinnate; pinna? 

 mostly opposite, 8-12 pairs on short but distinct stalks, roundish ovate (3 X/ 

 4" long), cuueate at the lower side of the base, and truncate at the upper side, 

 crenate or serrate, obtuse ; fruit-dots 6-8 on each pinna, elongated, the one 

 next the rachis often double. Carolina (Th. Moore), Florida (Binney). 

 Fertile fronds 4' -6' high, the stipe as long as the sterile fronds. 



4. A. Trichomanes, L. Stipe and rachis slender, purplish black and 

 shining; fronds many from the short rootstock, linear, pinnate ; pinnce numer- 

 ous, minute (2" - 3" long), roundish oblong, narrowed at the base and attached 

 to a raised point on the rachis; fruit-dots 4-8 on a pinna. (A. melano- 

 caulou, Willd.) Rocks along the Alleghanies, and northward. Fronds 

 4' -8' high. 



5. A. ebeneum, Aiton. Stipe and rachis purplish black and shining ; 

 fronds linear-lanceolate or spatulate, acuminate, pinnate ; pinnae numerous, 

 sessile, linear: oblong, auricled on one or both sides of the base, serrate or 

 nearly entire, those below the middle of the frond gradually shorter and de- 

 flexed ; fruit-dots 10- 13 on a pinna. Florida to Mississippi, and northward. 

 Fronds 6' - 18' high, 1' - 3' wide ; stipe very short. 



6. A. ebenoides, R. R. Scott. Frond thin, broadly lanceolate, pinnate 

 below, pinnatifid above, long-attenuate and often rooting at the apex, 4' - 9' 

 long; pinnae lanceolate from a broader base, 3"- 9" long. Shady ravines, 

 Central Alabama, and northward. Rare. 



7. A. parvulum, Mart. & Galeotti. Frond rigid, lanceolate, pinnate, 

 2'- 8' long; pinnae nearly opposite and sessile, oblong, entire or crenulate, 

 auricled on one or both sides at the base, 2" - 6" long ; sori half-way between 

 the margins and midrib. Calcareous rocks, Florida to Tennessee. 



8. A. flrmum, Kunze. Rootstocks short ; frond ovate or oblong, pin- 

 nate, rather longer than the pale smooth stipe, 12' or less long; pinnae (about 

 12) lanceolate or oblong, obtuse, serrate, the terminal one attenuate ; sori in 

 two rows. Marion County, Florida (J. D. Smith). 



9. A. angUStifolium, Michx. Fronds tall, lanceolate, pinnate ; pinnae 

 numerous ; the sterile ones lanceolate from a truncate base ; the fertile ones 

 narrower, and bearing 60 - 80 curved fruit-dots on the upper branches of the 

 pinnate forking veins; iudusia thickish, strongly convex. Rich soil along 

 the mountains. Fronds l-3 high, annual. Pinnae 2' -4' long, 4" -8" 



wide. 



* * * Fronds 2 - S-pinnate or pinnatifid. 



10. A. montanum, Willd. Fronds small, ovate-lanceolate, pinnate ; 

 pinnae .few, petjoled, ovate or triangular; the lower ones pinuatifid ; the upper 



