FILICES. 447 



ORDER CXLI. FILICES. Juss. Lind. 



Fructification only of one kind on the same individual. 

 Capsules spiked or racemed, or mostly collected into clusters 

 of various' shapes (sori) upon the back of the leaf or frond, 

 naked or covered with an involucre, often surrounded by an 

 elastic ring and opening irregularly, or without a ring and 

 opening with a regular fissure. Seeds or sporules minute. 



Leafy plants with a horizontal stem or caudex (rliizoma.) 

 Fronds before expansion, circinate, simple or variously branch- 

 ed and divided. 



Div. I. POLYPODIACE.E. Capsules furnished with a verti- 

 cal usually incomplete ring, bursting irregularly and trans- 

 versely. 



1. POLYPODIUM. Linn. 



Sori roundish, scattered on various parts of the lower sur- 

 face of the frond. Involucre none. 



* Frond pinnatifid. 



1. P. vulgar c Linn. : frond smooth, deeply pinnatifid; segments ob- 

 long-obtuse, slightly serrate, the upper ones becoming gradually smal- 

 ler ; sori solitary and P. virginianum Willd. 



HAB. Rocky woods. Arc. Amer. to Car. W. to Miss. July. 

 2_. Fern 610 inches high. Root creeping, clothed with 

 brownish chaffy scales. Stipe smooth. Sori large, in double 

 rows, yellowish, at length dark coloured. ,/v,y 



** Frond bipinnatifid. 



2. P. hexagonopterum Mich. : frond bipinnatifid, rather smooth, the 

 lower divisions deflexed ; segments lanceolate, obtuse, ciliate ; lower 

 ones deeply crenate ; upper ones very entire ; the lowest adnate-de- 

 current; sori minute ; stipe smooth. 



HAB. Moist woods. Can. to Car. July. If. Fern 1218 

 inches high. Frond forming a triangle in its circumference, 

 connected by a sort of hexagonal membrane ; the 2 3 lower 

 divisions often deflected. Sori very minute. 



3 P. phegopteris Linn. : frond bipinnatifid, the two lower divisions 

 deflexed ; segments linear-lanceolate, obtuse, entire., ciliate, the lower- 

 most ones adnate-decurrent ; veins hairy ; sori solitary, marginal. 

 P. connectile IViUd. and the American authors. 



HAB. Shady woods. Throughout the U. S. July, Aug. If .* 

 A careful comparison of specimens has satisfied me that our 

 plant is not distinct from the foreign one. It differs from the 

 preceding in having a chaffy stipe and larger sori. The whole 

 fern also is smaller. 



