FILICES. 461 



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

 rounded on the upper. 



Moist woods. Cjm. to Maj's. and N. Y. July. %.~-Fer7i\—2 feet high, 

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

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

 Indusium vaulted, thick. Narrow-leaved Spleenwort. 



2. A. ebeneum Willd. : 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. trichomanoides Mich. A. po- 

 hjpodioides Muhl. 



Rocky woods. Can. to Car. July. %. — Fern 8 — 12 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 pinnse, at length confluent. Indusium thin and 

 membranaceous. Ebony Spleenwort. 



3. A. Trichomanes Linn. : frond pinnate ; pinn£e obhquely oval or round- 

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

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



Shady rocks. Cart, to Car. July. %. — Fern 4 — 8 inches high, growing in 

 dense spreading tOfts. 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-pinnalijid. 



4. A. thelypterioidcs Mich. : frond pinnate ; pinnse sessile, oblong-lanceo- 

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

 serrate. 



Shady banks of streams. Can. to Car. July. %..—Fern 1—2 feet high. 

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

 cous green; pinncB 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. %. — Fern 2 — 4 inches long, 

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

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



Wall-rue Spleenwort. 



6. A. 7nontanum 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 Gar. Schweimtz. July. %—Fern 

 4 — 8 inches high, growing in tufts. Frond having a narrow outline, mostly bi- 

 pinnate, but more or less divided according to its size. Soi-i 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 famina Bernh. : frond bipinnate ; pinnules linear-oblong ; 

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

 eori oblong, at length lunate and recurved. Aspidiiivi Filix fxmina and 



