F1LICES. 457 



* Leafy frond bearing fruit. 



1. O. claytoniana Linn. : frond pinnate ; pinnae pinnatifid, with 

 smaller fertile ones at the top. 



HAB. Wet grounds. Cambridge, N. Y. Stevenson. Penn. Con- 

 rad. May. 14-. Frond 12 18 inches high ; pinnee obtuse, to- 

 mentose at the axils ; segments entire. Fruit terminal, bipin- 

 nately panicled, erect, ferruginous. Identified by Muhlenberg 

 with O. interrupta Mich., and by Pursh with O. dnnamomea. 

 From the former it differs in having the fructification terminal, 

 and from the latter by having the pinnae more obtuse, the seg- 

 ments closer and not so deep, and by not being lanuginous. See 

 Conrad in Jour. Phil. Acad. vi. 39. 



2. O. interrupta Mich. : frond pinnate, smooth ; pinnoe nearly op- 

 posite, pinnatifid ; segments oblong, subacute, entire ; some of the 

 intermediate pinnae fruit-bearing. 



HAB. Low grounds. Can. to Vir. June. 2J.. Fern 1 2 feet 

 high. Frond with 2 or 3 central pairs of pinnse fertile dark 

 brown and shorter than the sterile ones. 



3. O. spectabilis IVilld. ; frond bipinnate, all fruit bearing at the sum- 

 mit; pinnules oblong, distinct, serrulate; raceme very large, decom- 

 pound. O. regalis Mich. Torr. 



HAB. Low grounds and swamps. Can. to Flor. July. 2. 

 Fern 3 4 feet high, of a grayish colour, with numerous spread- 

 ing branches. Differs from the foreign O. regalis by its being 

 smaller, and of a more rigid texture, and by the distinct petiola- 

 tion of the pinnules which are not lobed at base. 



* * Fertile fronds separated. 



4. O. dnnamomea Linn. : sterile frond pinnate ; pinnae pinnatifid ; 

 segments ovate-oblong, obtuse, very entire ; fertile frond bipinnate, 

 woolly, contracted ; stipe woolly. 



HAB. Low grounds. Can. to Flor. Aug. Z. Sterile fronds 

 from 2 5 feet high, arranged in bundles or circles, with a few 

 much smaller fertile ones in the midst. 



15. LYGODIUM. Swartz. 



Capsules sessile, ovate, in 2-ranked little spikes, which is- 

 sue from the margin of the frond, radiate-striate, or wrinkled, 

 opening on the inner side, from the base to the summit. In- 

 volucre scale-like, covering each capsule. 



L. palmatum Swartz. : stem flexuous and climbing ; fronds conju- 

 gate, cordate, palmate, with 5 lobes ; lobes entire, obtuse ; spikelets 

 oblong-linear, in a compound terminal spike. Hydroglossum palma- 

 tum WiUd. Pursh. Cteisium paniculatum Mich. 



HAB. Low woods. Mass, to Car. ; rare. July. 1. Stem 

 climbing, 34 feet long, smooth and slender. Petioles alter- 

 nate, forked at a short distance from the stem, and supporting 

 2 leaves or fronds, which are divided into 5 9 oblong obtuse 



39 



