FILICES. (ferns.) GG7 



* Fronds hip innate. 

 11. A. acule&tum, Swarte, VW. Braunii, Koch. Frond spreading 

 (li°-2° long), oblong-lanceolate in outline, with a tapering base, the lower of 

 the many pairs of oblong-lanceolate pinna; gradually reduced in size and obtuse ; 

 pinnules ovate or oblong, obtuse, truncate and almost rectangular at the base, 

 short-stalked, or the upper confluent, sharply toothed, beset with long and soft 

 as well as chaffy hairs. (A. Braunii, Spenner.) — Deep woods, mountains of 

 New Hampshire, Vermont, N. New York, and northward. (Eu.) 



13. CYSTOPTERIS, Bernhardi. Bladder-Fern. (PI. 18.) 



Fruit-dots roundish, borne on the back of a straight fork of the free veins ; 

 the delicate indusium hood-like or arched, attached by a broad base on the inner 

 side (towards the midrib) partly under the fruit-dot, early opening free at the 

 other side, which looks toward the apex of the lobe, and is somewhat jagged, 

 soon thrown back or withering away. — Tufted Ferns with slender and delicate 

 twice or thrice pinnate fronds ; the lobes cut-toothed. (Name composed of kucttis, 

 a bladder, and 7rre pis, fern, from the inflated indusium.) 



1. C. bulbifera, Bcrnh. Frond lanceolate, elongated (l°-2° long), 

 2-pinnatc; the pinna; lanceolate-oblong, pointed, horizontal (l'-2' long) ; the 

 rhachis and pinna often bearing bulblets underneath, wingless; pinnules crowded, 

 oblong, obtuse, toothed or pinnatifid ; indusium short, truncate on the free side. 

 (Aspidium bulbiferum, Swartz. A. atomarium, Muld. !) — Shaded ravines, 

 &c. : common. July. 



2. C. fragilis, Bernh. Frond oblong-lanceolate (4' -8' long, besides the 

 stalk which is fully as long), 2-3-pinnate; the pinnae and pinnules ovate or lan- 

 ceolate in outline, irregularly pinnatifid or cut-toothed, mostly acute, decurrent 

 on the margined or winged rhachis ; indusium tapering or acute at the free end. — 

 Var. dentaxa, Hook., is narrower and less divided, barely twice pinnate, with 

 ovate obtuse and bluntly-toothed pinnules. (Aspidium te'nue, Swartz.) — Shaded 

 cliffs: common, and very variable. July. (Eu.) 



14. STRUTHIOPTERIS, Willd. Ostrich-Fern. (PI. 15.) 



Fruit-dots round, on the pinnae of a separate contracted and rigid frond, the 

 margins of which are rolled backward so as to form a somewhat necklace-shaped 

 or continuous hollow body enclosing the fruit : there are 3-5 pinnate free vcinlcts 

 from each primary vein, each bearing a fruit-dot on its middle : fruit-dots crowded 

 and confluent ; the sporangia borne on an elevated receptacle which is half-encir- 

 cled at its base by a very delicate semicircular and ragged evanescent indusium. 

 — Sterile fronds large, very much exceeding the fertile, pinnate, the pinna; 

 pinnatifid, all growing in a close circular tuft from thick and scaly matted 

 rootstocks. Stipes stout, angular. Pinnate veins free and simple. (Name 

 compounded of o-rpovdos, an ostrich, and Trrepls, a fern, from the plume-like 

 arrangement of the divisions of the fertile frond.) 



1. S. Germailica, Willd. Sterile fronds smooth, broadly lanceolate, the 

 lowest pinnae gradually much smaller; pinnae very numerous, narrowly lance- 

 olate, deeply pinnatifid ; the lobes oblong, obtuse : fertile frond with somewhat 



