Order 1G0.— FILICES. 821 



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

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



§ Atiiyrium. Inclusium oblong, subrcniform, opening half around. Frond bipinnate... JJo. 7 

 § Asi'lenium proper. lndusium narrow, stmightisli, opening only on one. edge, (a) 



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



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



a Frond simply pinnate, — thin, large, with green stalks No. :t 



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



1 A. Trichomanes L. Dwarf Spleenwout. Frond pinnate ; Ifts. roundish, sut- 



sessile, small, roundish-obovate, obtusely cuneate and entire tit base, ereuate 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 roundish, sessile 

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

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



2 A. ebeneum Willi Ebony Spleenwout. Frond pinnate ; Ifts. lanceolate, sub- 

 falcate, serrate, auriculate at base on the upper side; stipo smooth and polished. — 

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

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

 in outline. Leaflets near an inch in length, rather acuminate and curved at apex, 

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

 in*Short lines on each side the midrib. July. 



3 A. angustifdlium Michx. Frond pinnate; Ifts. alternate, upper ones sub- 

 opposite, linear-lanceolate, serrate towards the apex, somewhat repand, the baso 

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

 Vt. to Ga. Fronds thin, fragile, 1 — 2f high, in tufts, t!:o outer ones barren, inner 

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

 confluent. July. 



4 A. Ruta-muraria L. Frond bipinnate at base, simply pinnate above; Ifts. 

 small, petiolate, cuneate at lose, erose-dtntaie at the Hunt apex. — An extremely 

 small and delicate fern, in dry, rocky places. Frond 2 — 'S' high, i as wide, smooth, 

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

 than $' l° D o- Stipe flat and smooth. Sori linear-oblong, slightly oblique, of a 



■ rusty-brown color, linally confluent. July. 



5 A. montanum Villd. (A. Adiantum-nigrum. Michx.) Frond glabrous, 

 bipinnate ; Ifts. oblong-ovaie, parted into a few (5 or G) 2 or 3-iooihed segment; ; 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 iu the foreign A. Adiantum-nigrum. July. 



6 A. thelypteroidea Michx. Silvery Spleenwout. Frond bipinnatifld ; Ifts. 

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

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

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

 Leaflets distinct and rather remote, narrow, 4 — G' long. Segments rounded at tha 

 end, near V long. Sori arranged in 2 rows on each segment, one on each sido 

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



7 A. Filix-fcemina Bernh. Frond bipinnate ; Ifts. lanceolate, acuminate ; seg. 

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

 or lunate, arranged near tho 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 cut into oblong, deep 

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

 Sori large, at first in linear curves, finally confluent, giving tho whole frond a dark 

 brown hue. July. (Aspidium, Swtz.) 



15. ANTIGRAM'MA, Prcsl. Walking Fern. (Gr. avri, like, 

 ypd^tjia, writing; said of the fruit dots.) Sori linear or ohlong, 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 iu the margin. 



