Obdbr 160.~FILIOES. 821 



the upper or forward side of the lateral veins and opening towards the 

 midvein. — Ferns of various habit. Veins forked or pinnate. 



§ Atiiyrium. Indusium oblong, subreniform, opening half aronnd. rrondbipinnate..,Ko. 7 

 § ASPLENIUM proper. Indusiiim narrow, straightisb, opening only on one edge, (a) 



a Frond bipinnatifld, with numerous pinnie (leaflets). Stalks green No. 6 



a Frond bipinnatifld, with few divisions. Stalks greenish Nos. 4, 5 



a Frond simply i>innate, — thin, large, with gi-een stalks No. 8 



— subcoriaceous, with dark purple stalks Nos. 1, 2 



1 A. Trichomanes L. Dwaep Spleenwoet. Frond pinnate ; Ifls. roundish, sub- 

 sessile, small, roundish-obovate, obtusely cuneate and entire at base, crenate above ; 

 stipe black and polished. — A small and delicate fern, forming tufts on shady rocks. 

 Frond 3 — 6' high, lance-linear in outline, with 8 — 12 pairs of roundfsh, sessile 

 leaflets, 3 — 4" long. Fruit in several linear-oblong, finally roundish sori on each 

 leaflet, placed oblique to the midvein. July. (A. melanocaulon Muhl.) 



2 A. ebeneum Willd. Ebony Spleenwoet. Frond pinnate ; Ifts. lanceplaie, suh- 

 falcate, serrate, auriculaie at base on the upper aide ; stipe smooth and polished. — 

 A beautiful fern, in dry woods, hills. Fronds 8 — 14' high, on a slender stipe of 

 a shining brown or black color. Foliage 5 — 9' long, 1 — 1-J-' wide, linear-lanceolate 

 in outKne. Leaflets near an inch in length, rather acuminate and curve,d at apex, 

 dilated at base on the upper side, and sometimes on the lower. Fruit arranged 

 in short lines on each side the midrib. July. 



3 A. augustifolium Miohx. Frond pinnate; Ifls. alternate, upper ones sub- 

 opposite, hnear-lanoeolate, serrate towards the apex, somewhat repand, Ihe base 

 truncate on the upper side and rounded on the lower. — In low woods, frequent, 

 Tt. to Ga. Fronds thin, fragile, 1 — 2f high, in tufts, the outer ones barren, inner 

 fertile. Sori large, diverging from the midrib, parallel with the veins, at length 

 confluent. July. 



4 A. Ruta-nmrkria L. Frond bipinnate at base, simply pinnate above; Ifls. 

 small, petiolate, CMraeafe at hose, erose-dentate at the TAunt apex. — An extremely 

 small and delicate fern, in dry, rocky places. Frond 2 — 3' high, -J- as wide, smooth, 

 growing in tufts, somewhat coriaceous. Segments usually 3 on each leaflet, less 

 than y long. Stipe flat and smooth. Sori linear-oblong, slightly oblique, of a 

 rusly-brown color, finally confluent. ' July. 



5 A. montauum "Willd. (A. Adiantum-nigrum. Michx.) Frond glabrous, 

 bipinnate ; Ifls. oblong-ovate, parted into a few (5 or 6) 2 or 3-toothed segments ; sori 

 linear, finally confluent. — ^Mountain rocks, Penn. to Car. (Curtis), "W. to Ky. 

 Fronds growing in tufts, 4 — 8' high, rhombic or oblong-lanceolate in outline, 

 mostly bipinnate, but more or less divided according to the size. Segments more 

 obtuse than in the foreign A. Adiantum-nigrum. July. 



6 A. thelypteroidea Michx. Silvbet Spleenwoet. Frond bipinnatifld ; Ifts. 

 pinnatifid, oblong-lanceolate, acuminate ; segments oblong, obtuse, serrate-crenate ; 

 sori in parallel, oblique fines. — A fine, large fern, on shady banks of streams. 

 Fronds IJ — 3f high, of an ovate-acuminate outline, on a slightly chaffy, pale stipe. 

 Leaflets distinct and rather remote, narrow, 4 — 6' long. Segments rounded at tlie 

 end, near -J-' long. Sori arranged in 2 rows on each segment, one on each side 

 the midvein, convergent below, with shining, silvery indusia when young. July. 



7 A. Tilix-fcEmina Bemh. Frond bipinnate ; Ifts. lanceolate, acuminate ; seg. 

 oblong-lanceolate, deeply cut-pinnatifid ; ultimate seg. 2 — 3-toothed ; sori reniform 

 or lunate, arranged near the veins ; stipe smooth. — A delicate, finely-divided fern 

 in moist woods. Fronds 1 — 2f high, with subopposite divisions. These are sub- 

 divided into distinct, obtuse segments, which are themselves out into oblong, deep 

 BBrratures, and lastly, the serratures are mostly with 2 — 3 teeth at the summit. 

 Sori large, at first in Mnear curves, finally confluent, giving the whole frond a dark 

 brown hue. July. (Aspidium, Swtz.) 



i5. ANTIGRAM'fflA, Presl. Walking Fern. (Gr. avri, like, 

 ypdniia, writing ; said of the fruit dots.) Sori linear or oblong, scat- 

 tered without order on the transverse veins, oblique at various angles, 

 often in pairs and facing each other ; indusium simple, linear. — Frond 

 simple, veins reticulated in the midst, forked and free only in the margm. 



