WOODSIA. CLXIV. FILICES. 631 



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. 



5. A. THELiPTERoiDEs. Michx. Silvery Spleenwort. 



Frond bipinnatifid ; Ifts. 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 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 i'long. Sori arranged 

 in 2 rows on each segment, one on each side the midvein, convergent below, 

 with shining, silvery indusia when young. July. 



6. A. FILIX-FCEMINA. Bernh. (Aspidium Filix-foemina and asplenoides. Sw. 



A. angustum. W.) Frond bipinnate ; Ifts. lanceolate, acuminate ; seg. ob- 

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

 or lunate, arranged near the 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 the whole frond a 

 dark brown hue. July. 



7. A. RUTA-MURARIA. WaU-rue Spleenwort. 



Frond bipinnate at base, simply pinnate above ; Ifts. small, petiolate, cu- 

 neate, obtusely dentate above. An extremely small and delicate fern, in dry, 

 rocky places." Frond 2 3' high, as wide, smooth, growing in tufts, somewhat 

 coriaceous. Segments usually 3 on each leaflet, less than \' long. Stipe flat 

 and smooth. Sori linear-oblong, slightly oblique, of a rusty -brown color, finally 

 confluent. July. 



8. A. MONTANUM. Willd. (A. Adiantum-nigrum. Michx.) 



Frond glabrous, bipinnate ; Ifts. oblong-ovate, pinnatifid ; seg. 2 3-toothed 

 at the apex : sori linear, finally confluent. Mountain rocks, Bethlehem, Penn. 

 Schwenitz (fide Beck), S. to Car., W. to Ky. Fronds growing in tufts, 4 8' 

 high, narrowly 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. 



4. WOODSIA. Brown. 



In honor of Joseph Woods, an excellent English botanist. 



Sori roundish, scattered ; indusium beneath the sorus, open, with 

 a multifid or fringed margin, including the pedicellate thecse, like a 

 calyx. 



1. W. ILVENSIS. Br. (Polypodium. Willd.) 



Frond pinnate, leaflets pinnatifid, lanceolate ; segments ovate-oblong, ob- 

 tuse ; sori near the margin, at length confluent ; rachis and stipe chaffy. Grow- 

 ing in tufts, on rocks and in dry woods. Fronds 5 or 6' high, on chaffy and 

 woolly stipes, most chaffy af base. Foliage 3 or 4' long, as wide, oblong- 

 lanceolate in outline, woolly or chaffy beneath, with opposite and alternate leaf- 

 lets about an inch in length. The lower leaflets are pinnatifid, upper ones 

 wavy on the margin or entire. June. 



2. W. PERRINIANA. Hook. & Grev. (Hypopeltis obtusa. Torr.) 

 Frond subbipinnate, minutely glandular-pilose ; segments of the leaflets pin- 

 natifid; ultimate segments roundish-oblong, obtuse, bidentate ; sori submarginalf 

 stipe somewhat chaffy. About a foot high, among and on rocks. Fronds lancft 

 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 subtended by a half round indusium notched into little 

 teeth on the margin. July. 



3. W. HYPERBOREA. Br. (Polypodium. Willd.') Flower-cup Fern. 

 Frond pinnate ; Ifts. suborbicular, subcordate, 3-parted or incisely pinnati- 

 fid, cuneate at base, rough pilose beneath. A very small species, much resem- 



