gS Our Native Ferns. 



sions ; indusium very delicate, deeply cleft into lacinise which ter- 

 minate in short hairs. Col., Ariz., Cal., Ore., and northward. IV. 



5. ^W. Oregana,* D. C. Eaton. Stalks and fronds Smooth ; 

 fertile fronds taller than the sterile ones; pinnae triangular-oblong, 

 pinnatifid; segments oblong or ovate, toothed or crenate ; teeth 

 often reflexed and covering the submarginal sori ; indusium very 

 minute, divided almost to the centre into a few beaded hairs. 

 Ariz., Utah, Co!., Ore, and northward. 11. 



\ 1. HYPOPELTIS, Torr. Indusium conspicuous, at first en- 

 closing the sporangia, but early opening at the top, and splitting 

 into several spreading jagged lobes. 



6. W. obtusa, Torr. Stipes not jointed, 3' — 6' long ; fronds 

 broadly lanceolate, minutely glandular-hairy, 6' — 12' high, nearly 

 bipinnate ; pinnae rather remote, triangular-ovate or oblong, pin- 

 nately parted ; segments oblong, obtuse, crenately toothed, the 

 lower ones pinnatifid; veins forked. N. Eng. to Ky. and west- 

 ward. 111. 



XXIV. DICKSONIA, L'Her. 



Sori small, globular, marginal or intra-marginal. Sporangia 

 borne in an elevated, globular receptacle, enclosed in a mem- 

 branous, cup-shaped indusium, which is open at the top, and on 

 the outer side partly adherent to a reflexed toothlet of the frond. 



I SITOLOBIUM, J. Sm. 



I. D. punctilobula,* Kunze. Rhizoma slender, extensively 

 creeping, naked; stipes stout, chaffless; fronds 1° — 2>^° long, 5' — 

 9' bro.id, ovate-lanceolate and pointed, usually tripinnatifid ; pinnas 

 lanceolate, pointed ; pinnules cut into oblong and obtuse cut- 

 toothed lobes ; rachis and under surface minutely glandular and 

 hairy ; sori minute, each on a recurved toothlet, usually one at the 

 upper margin of each lobe. Can. to Tenn. III. 



XXV. TRICHOMANES, Sm. Filmy-fern.. 



Sori marginal, terminating a vein more or less sunken in the 

 frond. Sporangia sessile on the lower part of a cylindrical, fili- 

 form, often elongated receptacle. Indusia tubular or funnel- 

 shaped, entire or two-lipped at the mouth. Fronds dehcate, 

 pellucid. 



\ EUTRICHOMANES. 



I. T. Petersii,* Gray. Stipes i" — 2" long; fronds 3"— 10" 

 long, \" — 2" broad, oblong-lanceolate or obovate, entire or vari- 

 ously pinnatifid, the younger ones with a few black hairs along the 



