630 CLXIV. FILICES. Asplenium. 



decurrent leaflets; stipe chafiy at base. — A delicate fern, on moist rocks, fre- 

 quent. Fronds 6 — 12' high, dark green, its divisions rather remote, and with 

 the subdivisions, considerably variable in form. Sori large and numerous, 

 near the margins of the segments. June, July. 



8. A. ACULEATUM. Sw. Prickly Shield-Fern. 



SegTtieiits of the leafiets ovate, subfalcate, acute, aculeate-serrate, upper 

 ones truncate at base, louver cuneate at base ; only the upper Uajlets fertile ; 

 stipe and rachis chafiy. — Mansfield Mt., Vt., and Mts. in Essex Co., N. Y., 

 Macrae. Fronds dark green, in tufts 1 — 2f high. Segments of the leaflets on 

 very short petioles, somewhat dilated at base on the upper side, deeply serrate, 

 each serrature tipped with a short spinose bristle. Sori brown, in single rows, 

 distinct. Indusium reniform. Aug. 



9. A. DiLATATUM. Sw. (A. spiuulosum, Willd. 7) Broad Shield-Fern. 

 Leafiets oblong-lanceolate, distinct ; segments distinct, oblong, obtuse, 



incisely pinnatifid ; ultimate segments mucronate-serrate ; stipe chafl?y ; indusium 

 urabilicate. — Woods and shady pastures. Fronds 1 — 2f high, nearly tripin- 

 nate, the foliage about twice as long as wide, acuminate at apex, abrupt at 

 base. Leaflets also acuminate, but the segments rather obtuse, all distinct at 

 base, except those near the summit, serratures with short, soft bristles. Stipe 

 with large, tawny scales. Sori rather large, somewhat in 2 rows. Jl. 



10. A. BULBiFERUM. Sw. (Cistoptcris. Bernh.') Bulbiferous Shield-Fern. 

 Frond bipinnate, oblong-lanceolate, segments opposite, oblong, serrate, the 



lower one pinnatifid ; rachis bulbiferous ; so?-i roundish, the indusium attached 

 to one side. — In damp woods, frequent. Frond 12 — 18' high, remarkable for 

 the little bulbs produced in the axils of the rachis, which, falling to the ground, 

 take root. Foliage narrow, tapering to an acuminate summit. Stipe smooth. Jl. 



3. ASPLENIUM. 



Ch'. a, privation, cTr\rjv, the spleen; from its supposed medicinal virtues. 



Sori linear, oblique, or somewhat transverse, scattered ; indusium 

 arising from the lateral veins and opening longitudinally, usually 

 towards the midvein. 



1. A. RHizoPHYLLUM. Willd. Walking Fern. 



Frond mostly undivided, lanceolate, stipitate, subcrenate, cordate-auricu- 

 late at base, the apex attenuated into a long, slender acumination, rooting at 

 the point. — This singular fern grows in rocky woods, not very common. The 

 frond is 4 — 8' long ; the long, slender, linear point bending over backwards, 

 "caches the earth, and there strikes root, giving rise to a new plant. Though 

 usually with slightly crenate margins, the plant varies by imperceptible degrees, 

 becoming sometimes so deeply crenate as to form a well-marked variety with 

 pinnatifid fronds. July. 



2. EBENEUM. Willd. Ebonij Spleenwort. 



Frond pinnate ; Ifts. lanceolate, subfalcate, serrate, auriculate at base on 

 the upper side ; stipe smooth and polished. — A beautiful fern, in dry woods, 

 hills, &c. Fronds 8 — 14' high, on a slender stipe of a shining brown or black 

 color. Foliage 5 — 9' long, 1 — 1^' wide, linear-lanceolate in outline. Leaflets 

 near an inch in length, rather acuminate and curved 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. ANGUsTiFOLiuM. Michx. Swamp Spleenwort. 



Frond pinnate ; Ifts. alternate, upper ones subopposite, linear-lanceolate, 

 serrate towards the apex, somewhat repand, the base truncate on the upper side 

 and rounded on the lower. — In low woods, frequent. Fronds 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. Trichomanes. (A. melanocaulon. Muhl.) Dwarf Spleenwort. 

 Frond pinnate ; Ifts. roundish, subsessile, 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 



