piLiCEs. 459 



olate ; segments oblong, obtuse, crenate-serrate, decurrent, the lower ones 

 nearly distinct; sori nearly marginal, distinct, ' Nephrodium marginale 

 Mick. 



Rocky woods. Can. to Car. July. %. — Fern 12 — 18 inches high. Stipe 

 stout, chaffy, especially near the root, with large tawny scales. Frond ovate- 

 oblong, smooth, bluish-green, the upper part only fertile.- Sori middle-sized, 

 one at each notch in the segments. Indusiurn peltate-reiiilbrm. 



Marginal Shield-fern. 



7. A. dilatatuvi Sioartz : stipe chaffy ; frond bipinnate ; the pinnules 

 oblong, distinct, deeply and inoisely pinnatifid ; segments mucronate-ser- 

 rate; sori minute, distinct, in a double row about the middle of the pinnules. 

 A. intermedium Muhl. A, spinulosum Piirsk. Nephrodium cristaluvi MlcJi.. 



Shady woods. Can. to Virg. July. %. — Stipe 6 — 12 inches long, pale 

 brown, chaffy with thin brown scales. Frond 12— -18 inches long, ovate-laa 

 ceolate in its outline, varying in the divisions of the pinncB, sometimes almos* 

 tripinnate; serratures of the segments cuspidate or sharply acuminate. Sor^ 

 rather small, numerous, somewhat in two rows, brownish. Indusiurn umbilicatt; 

 in the centre. Dilated Shield-fern. 



8. A. acukatum Sioartz: stipe and rachis chaffy; frond bipinnate; 

 pinnules ovate, somewhat falcate, slightly petioled, mucronate-serrate, ob- 

 liquely truncate and auricled at the base on the upper side, obtusely cuneate 

 on the lower, upper ones fructiferous. ( Torr. N. Y. Ft.) 



White mountains, N. H. Green Mountains, Vt. Mountains of Essex county, 

 N. Y. Aug. 11-. — Stipe 2 — 6 inches long, and with the rachis clothed with 

 chaffy lanceolate-subulate scales. Frond 1^ — 2 feet long, of a rigid texture, 

 broad-lanceolate in its outline. Sori rather large, 6 — 8 on each pinnule, near 

 the middle. Indusiurn reniform-peltate. Prickly Shield-fern. 



4. WOOD SI A. Broion.—Woodsia. 

 (Named in honor of Joseph Woods ; an English botanist.) 



Sori globose. Indusiurn more or less globose or cup-shaped, 

 seated under the sorus, and at length cut at the margin into 

 numerous often capillary segments. Spore-cases globose, pedi- 

 cellate. 



1. W. Ilvensis Brown: frond lanceolate, pinnate; pinnae oblong, obtuse, 

 deeply pinnatifid ; segments oblong, obscurely crenate, the under surface as 

 well as the rachis and stipe chaffy. W. Itmnsis and rufidula Beck Bat. 

 1st. Ed. Polypodium ILvense Swartz. 



Rocky banks of streams. Subarct. Amer. to Car. June. %. — Fern 4 — 6 

 inches high, growing in dense tufts. Fronds 2—4 inches long, the under surface 

 clothed with rusty scales ; pinncB about 12, alternate. Sori small, near the 

 margin of the segments, at length confluent. Indusiurn surrounding the slightly 

 pedicellate spore-cases, the margin cut into numerous capillary segments. 



Oblong-leaved Woodsia. 



2. W. hyperborea Brmon : frond lanceolate, pinnate ; pinnse ovate-cordate, 

 incisely pinnatifid, covered with chaffy hair beneath ; segments rounded, 

 unequal. Polypodium hyperboreum Swartz. 



In clefts of rocks. Can. and on the high mountains of Penn. and Virg 

 Pursh. July. %. — Resembles the preceding, but is sometimes quite small, and 

 diflers in having the pinnse as well as tlie segments more rounded and less deeply 



