FILICES. 461 



nate-serrulate, somewhat repand ; the base truncate on the lower side, 

 rounded on the upper. 



Moist woods. Can. to Mats, and N. Y. July. %. Fern 12 feet high, 

 erect. Sterile fronds forming a circle with the fertile ones smaller and central. 

 Sort oblong-linear, diverging like veins from the midrib, at length confluent. 

 Indusium vaulted, thick. Narrow-leaved Spleenwort. 



2. A. ebeneum Willd.i frond pinnate; pinnae sessile, lanceolate, some- 

 what falcate, serrate, auriculate on the upper side of their base ; stipe and 

 rachis smooth and shining, dark purple. A. trickomoiwides Mich. A. po- 

 lypodioides Muhl. 



Rocky woods. Can. to Car. July. 1\.. Fern 812 inches high, erect. 

 Stipe very smooth, dark purple or nearly black. Frond lance-linear in its out- 

 line, pale green, smooth. Sori in short diverging lines, arranged in a double 

 row along the midrib of the pinnae, at length confluent. Indusium thin and 

 membranaceous. Ebony Spleenwort. 



3. A. Trichomanes Linn. : frond pinnate ; pinnae obliquely oval or round- 

 ish-obovate, subsessile, crenate, cuneate or cuneate-truncate at base ; stipe 

 and rachis smooth, shining, very dark purple. A. melanocaulon Wittd. 



Shady rocks. Can. to Car. July. 1\.. Fern 4 8 inches high, growing in 

 dense spreading tufts. Stipe slender, smooth and shining, blackish-purple. 

 Frond lance-linear in its outline, dark green. Sori 2~ 6 on each pinna, linear- 

 oblong, at length nearly oval. Common Rock Spleenwort. 



** Frond pinnate-pinnaiifid. 



4. A. thelypteriffides Mich. : frond pinnate ; pinnae sessile, oblong-lanceo- 

 late, acuminate, deeply pinnatifid ; segments oblong, obtuse, denticulate- 

 serrate. 



Shady banks of streams. Can. to Car. July. 1\.. Fern 12 feet high. 

 Stipe smooth, straw-color, slightly chaffy. Frond oblong-lanceolate, pale glau- 

 cous green ; pinnce long, numerous, distinct. Sori oblong and oblique, forming 

 two rows, one on each side of the partial rib, at length almost confluent. 



Thelypteris-like Spleenwort. 



*** Frond bipinnate. 



5. A. Ruta muraria Linn. : frond bipinnate at base, simply pinnate at 

 the top ; segments rhomboid-cuneate, obtusely denticulate at the extremity. 



Limestone rocks. N. Y. to Car. ; rare. July. 7^. Fern 2 4 inches long, 

 growing in tufts. Frond ovate, spreading, smooth, rather rigid, glaucous green. 

 Sort linear-oblong, slightly oblique, at length of a darker color and confluent. 



Wall-rue Spleenwort. 



6. A. montanum Willd. : frond smooth, bipinnate ; pinnules oblong- 

 ovate, pinnatifid ; segments 2 3-toothed at the apex. A. Adiantum ni- 

 grum Mich. 



Mountain rocks. Bethlehem, Penn. to Car. Schweimtz. July. 7J. Fern 

 48 inches high, growing in tufts. Frond having a narrow outline, mostly bi- 

 pinnate, but more or less divided according to its size. Sort linear, at length 

 confluent. Differs from the foreign A. Adiantum nigrum in being much smaller, 

 and in having the segments more obtuse. Mountain Spleenwort. 



7. A. Filix fcemina Bernh. : frond bipinnate ; pinnules linear-oblong ; 

 segments oblong-lanceolate, incised-serrate, the serratures 2 3-toothed; 

 son oblong, at length lunate and recurved. Aspidium Filix foKmina and 



