822 ORDER 160. FILICES. 



1 A. rhyzoph^-lla J. Smith. Frond mostly undivided, lanceolate, stipitate, sub- 

 crenate, cordate-auriculate at base, the apex attenuated into a long, slender acu- 

 mination, 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, reaches the earth, and there strikes root, giving rise to a new plant, 

 Thus the plant may walk by yearly steps. July. (Asplenium, ed. 2. Camptosorus. 

 Link.) 



2 A. pinnatifida. Frond pinnatifid, lanceolate, abrupt at base, the apex atten- 

 uated into a long acumination and sometimes striking root; segments or lobes 

 roundish-ovate ; sori irregularly scattered, at length large and confluent, covering 

 the lobes, and even the slender summit. Crevices of rocks, on the banks of the 

 Schuylkill (Nuttall), Ky. and Tenn. (Curtis) rare. Fronds tufted and spreading, 

 4 to 8' long. (Asplenium, Nutt.) 



16. SCOLOPEN'DRIUM, Smith. HART'S-TONGUE. (Gr. onoXo^vdpa, 

 the centipede ; suggested by the appearance of the under side of the 

 leaf.) Sori linear, transverse, scattered ; indusium double (arising from 

 2 contiguous parallel veins), occupying both sides of the sorus, along 

 the middle, finally opening lengthwise. 



S. officinanim "Willd. Frond simple, ligulate, acute, entire, cordate at base. 

 Shady rocks, Chittenango, K Y., (Sartwell.) Stipe rather short (3 5' long), chaffy, 

 bearing the frond suberect, 8 15' high, 2 3' wide, bright green, paler beneath. 

 Sori oblique to the midvein, 6 9" in length. Rhizoma large, creeping. July. 

 This curious fern appears to be confined to the vicinity above mentioned, where 

 it was first detected by Pursh. It is there abundant. (Asplenium Scolopen- 

 drium L.) 



17. WOOD'SIA, Brown. ROCK POLYPOD. (In honor of Joseph 

 Woods, an excellent English botanist.) Sori roundish, scattered ; indu- 

 sium beneath the sorus, early opening above it, with a multifid or fringed 

 margin, including the pedicellate spore cases, like a calyx. Small, caes- 

 pitous, ferns with pinnated fronds. 



HTPOPKLTES, Torr. Indusium closed over the sorus at first, toothed when open No. 1 



WOODSIA proper. ludusium concealed under the sorus, fringed with long hairs. . .Nos. 2, 3 



1 W. ilvensis Br. RUSTY POLYPOD. Frond pinnate, leaflets pinnatifid, lan- 

 ceolate ; segments ovate-oblong, obtuse ; sori near the margin, at length confluent; 

 stipe, rachis and midveins chaffy. Growing in tufts, on rocks and in dry woods 

 North and South. Fronds 5 or 6' high, on brown stipes which are more or less 

 chaffy. Foliage 3 or 4' long, as wide, oblong-lanceolate in outline, with rust- 

 colored chaff beneath, with opposite and alternate leaflets hardly an inch in 

 length. The lower leaflets are pinnatifid, upper ones wavy on the margin or en- 

 tire. (W. rufidula Beck.) 



2 W. obtftsa Torr. Frond subbipinnate, or nearly tripinnate, minutely glandu- 

 lar-pilous ; Ifts. distant ; segments of the leaflets pinnatifid ; ultimate segments 

 roundish-oblong, obtuse, bideutate; sori round, one at each cleft between the 

 lobelets, at length crowded ; stipe somewhat chaffy. About a foot high, among 

 and on rocks. N. Y. to Ky. and Tenn. Fronds lance-oblong in outline, 3 times as 

 long as wide. Segments of the leaflets crenate-serrate, the lower ones distinct, 

 upper confluent. Sori orbicular, becoming nearly confluent, each at first inclosed 

 in the silvery indusium which when open is notched into little teeth on the mar- 

 gin. July. (W. Perriniana, ed. 2.) 



3 W. glabella R. Br. Fern smooth and glabrous, pinnate, lance-linear in out- 

 line, 2 to 5' high ; Ifts. distant below, subopposite, ovate, very obtuse, a few lines 

 long, the upper with the margins only crenate, the lower deeply cleft into 3 to 7 

 lobelets; indusium fringed, open. Rocks, Little Falls, N". Y. (Yasey! in herb. 

 Curtis), Willoughby Mt., Vt. and Can. 



18. CISTOPTERIS, Bernh. BLADDER FERN. (Gr. KVOTIC, a blad- 

 der, Trreptf, fern.) Sori roundish; indusium hood shaped, vaulted, 



