2 A. Curtisii, N. sp. (We saw specimens of a new Adiantum in the herbarium of Rev. M. A. Curtis, from the Mts. of N. Car. But our notes are insufficient at present for its proper diagnosis.)
12. DICKSO'NIA L'Her. (In honor of James Dickson,a distinguished English cryptogamist.) Sori marginal, roundish, distinct, terminating a vein; indusium double, the proper one cup-shaped, opening outwards, the other formed of a reflected lobule of the margin and opening inwards.
D. pilosiuscula Willd. Fine-haired Mountain Fern. Frond bipinnate; leaflets lanceolate, sessile; segments pinnatifid, decurrent, oblong-ovate, ultimate segments toothed; stipe a little hairy. - A large and delicate fern, in pastures, roadsides, among rocks and stones. Fronds 2 - 3f high, in tufts, and remarkable for their numerous divisions and subdivisions. Stipe and rachis smooth, with the exception of a few, soft, scattered hairs. Leaflets alternate, approximate; segments deeply divided into 4-toothed, ultimate segments. Sori minute, solitary, on the upper margin of the segments. July. (D. punctilobula, Hook.)
13. WOODWAR'DIA, Sm. (To Thomas J. Woodward, an English botanist.) Sori oblong, straight, parallel with, and close to the midvein, on transverse, anastamosing veinlets; indusia arising from the same veinlet on the outer side, free and opening on the inner side towards the midvein. - Fronds pinnate or pinnatifid.
1 W. onocleoides Willd. Fronds of two kinds; the sterile simply pinnatifid pinnae, lanceolate, repand, slightly serrulate; fertile fronds pinnate, the pinnae entire, linear, acute. - In swamps, not common. Fern about a foot high, growing in tufts. Barren fronds numerous, of a narrow-lanceolate, acuminate outline. Leaflets with decurrent or confluent bases. Fertile fronds fewer, with linear segments nearly covered on the back with the fruit in oblong, longitudinal sori 1/4' in length. Aug. (W. angustifolia Sm.)
2 W. Virginica Willd. Fronds all similar, pinnate, very smooth, the leaflets pinnatifid, lanceolate, sessile; sori in interrupted lines near the midvein of the leaflets and oblong, obtusish segments. - In low woods and swamps. Frond about 2f high, on a smooth stipe, lanceolate in outline, and pale green. Leaflets alternate, deeply pinatifid, with numerous, spreading, obtuse and slightly crenate lobes. Fruit arranged in lines along each side of the midveins, both of the segments and leaflets. July, Aug. (Doodia, R. Br.)
3 W. thelypteroides Ph. Fronds nearly similar, pinnate, the pinnae sessile, villous at base, linear-lanceolate, pinnatifid; the segments in the sterile fronds oblong, obtusish, in the fertile short-triamgular, acute, all entire; stipe pubescent, angular. - Sandy
' swamps, near Charleston, S. Car. Resembles the preceding but is not half its size. Jl. (Pursh.)
14. ASPLE'NIUM, L. Spleenwort. (Gr. a, privative, the spleen; from its supposed medicinal virtues.) Sori linear, or linear-oblong, separate, oblique to the midvein, arising with its indusium, from the upper or forward side of the lateral veins and opening towards the midvein. - Ferns of various habit. Veins forked or pinnate.
§ Athysium. Indusium oblong, subreniform, opening half around. Frond bipinnate.................
§ Asplenium proper. Indusium narrow, straightish, opening only on one edge, (a)
a Frond bipinnatifid, with numerous pinnae (leaflets). Stalks green......................................
a Frond bipinnatifid, with few divisions. Stalks greenish....................
Nos. 4, 5
a Frond simply pinnate, - thin, large, with green stalks......................
- subcoriaceous, with dark purple stalks..........................................
Nos. 1, 2
1 A. Trichomanes L. Dwarf Spleenwort. Frond pinnate; lfts. roundish, sab-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 roundish, sessile leaflets, 3 - 4" long. Fruit in several linear-oblong, finally roundish sori on each leaflet, placed oblique to the mid vein. July. (A. melanocaulon Muhl.)
2 A. ebeneum Willd. Ebony Spleenwort. Frond pinnate; lfts. lanceolate, sub-falcate, serrate, auriculate at base on the upper side; 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 1/2' 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. Frond pinnate; lfts. alternate, upper ones sub-opposite, linear-lanceolate, serrate towards the apex, somewhat repand, the base 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, the 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; lfts. small, petiolate, cuneate at base, erose-dentate at the blunt apex. - An extremely small and delicate fern, in dry, rocky places. Frond 2 - 3' high, 1/2 as wide, smooth, growing in tufts, somewhat coriaceous. Segments usually 3 on each leaflet, less than 1/2' long. Stipe flat and smooth. Sori linear-oblong, slightly oblique, of a rusty-brown color, finally confluent. July.
5 A. montanum Willd. (A. Adiantum-nigrum. Michx.) Frond glabrous, bipinnate; lfts. 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. Silvery Spleenwort. Frond bipinnatifid; lfts. pinnatifid, oblong-lanceolate, acuminate; segments oblong, obtuse, serrate-crenate; sori in parallel, oblique lines. - A fine, large fern, on shady banks of streams. Fronds 1 1/2 - 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 the end, near 1/2' long. Sori arranged in 2 rows on each segment, one on each side the midvein, convergent below, with shining, silvery indusia when young. July.