820 Order lGO^-FILICES, 



il. ADIAN'TUM L. Maiden-hair. (Gr. a, privative, dia(vo), to 

 moisten ; as the rain slides off without wetting it.) Sori oblono- or 

 roundish, marginal ; indusia membranaceous, formed from the refiexed 

 margins of distinct portions of the frond and opening inwardly. — Stipe 

 polished. Ultimate segments dimidiate, the midvein on the lower 

 margin. 



1 A. pedatum L. Frond pedate ; divisions pinnate ; segments oblong-rhomboid, 

 incisely lobed on the upper side, obtuse at apex ; sori oblong, subulate. — This is, 

 doubtless, the most beautiful of all our ferns, abounding in damp, rocky woods. 

 Stipe 8 — 14' high, slender, of a deep, glossy purple approaching to a jet-black. 

 At top it divides equally into 2 compound branches, each of which gives off, at 

 regular intervals, C — 8 simply pinnate leaflets from the outer side, giving the 

 whole frond the form of tho crescent. July. 



2 A. Curtisii, N. sp. (We saw specimens of a now Adiantum in the herbarium 

 of Rev. At. A. Curtis, from the Mts. of N. Car. But our notes arc insufficient at 

 present for its proper diagnosis.) 



12. DICKStTNIA 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 ; leaf- 

 lets lanceolate, sessile; segments pinnatifid, decurrent, oblong-ovate, ultimato 

 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 tho 

 exception of a few, soft, scattered hairs. Leaflets alternate, approximate; seg- 

 ments deeply divided into 4-toothed, ultimato segments. Sori minute, solitary, on 

 the upper margin of the segments. July. (D. punctiloba 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 

 veinlct on tho outer side, free and opening on the inner side towards 

 the midvein. — Fronds pinnate or pinnatifid. 



1 W. onocleoide3 Willd. Fronds of two kinds; the sterile simply pinnatifid 

 pinnae, lanceolate, repand, slightly serrulate; fertilo fronds pinnate, the pinna? 

 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. Fertilo fronds fewer, with linear 

 segments nearly covered on the back with tho fruit in oblong, longitudinal sori \' 

 in length. Aug. (W. angustifblia Sm.) 



2 W. Virginica Willd. Fronds all similar, pinnate, very smooth, the leaflets pin- 

 natifid, lanceolate, sessile; sori in interrupted lines near the midvein of the leaflets 

 and oblong, obiusish segments. — In low woods and swamps. Frond about 2f high, 

 on a smooth stipe, lanceolate in outline, and pale green. Leaflets alternate, deeply 

 pinnatifid, with numerous, spreading, obtuse and slightly crenate lobes. Fruit 

 arranged in lines along each side of tho midveins, both of tho segments and leaf- 

 lets. July, Aug. (Doodia, R. Br.) 



3 W. thelypteroides Ph. Fronds nearly similar, pinnate, the pinna; sessile, villous 

 at base, linear-lanceolate, pinnatifid ; the segments in tho sterilo fronds oblong, obtus- 

 ish, in the fertile short-triangular, acute, all entire; stipe pubescent, angular. — Sandy 

 swamps, near Charleston, S. Car. Resembles the preceding but is not half ita 

 size. Jl. (Pursh.) 



14. ASPLE'NIUM, L. Spleenwort. (Gr. a, privative, onXrjv, the 

 spleen ; from its supposed medicinal virtues.) Sori linear, or linear- 

 oblong, separate, oblique to tho midvein, arising with its indusium, from 



