454 ACOTYLEDONOUS PLANTS. 



6. WOODWARDIA. Smith. 



Son oblong, distinct, parallel with the ribs of the frond on 

 cither side. Involucre superficial, arched, separating towards 

 the rib. 



1. W. onoclcoidts If'illd. : sterile frond pinnatifid ; segments lance- 

 olate, repand, slightly serrulate ; fertile frond pinnate ; segments li- 

 near, entire, acute. W. angustifulia Smith. MuhL 



HAB. Swamps. Can. to Flor. ; not common. Aug. 1. 

 . Fern a foot high, growing in tufts. Frond lanceolate, tapering 

 at the top. Sori a 1-4 of an inch long, at length nearly cover- 

 ing the back of the pinnce. 



2. W. tirginica Willd. : frond very smooth, pinnate ; pinntc ses- 

 sile, lanceolate, pinnatifid ; sori in interrupted lines near the midrib of 

 the pinnae and segments. W. banisteriana Mich. 



HAB. Swamps. N. Y. to Geor. July. Lf.^-Fern 2 feet high. 

 Stipe smooth. Frond having a lanceolate outline, light green, 

 with the segments acute and falcate. Sori in double lines, at 

 length confluent. 



7. SCOLOPENDRIUM. Smith. 



Sori linear, transverse, scattered. Involucre double, oc- 

 cupying both sides of the sorus, superficial, at length opening 

 longitudinally. 



S. offic'inarum Willd : frond simple, ligulate, entire, cordate at base. 

 Asplenium scolopcndrium Linn. 



HAB. Shady woods among loose rocks near Onondago, N. Y. 

 Pursh. July. Z. Frond suberect, on rather a short stipe, 

 8 15 inches long, 2 3 wide, fine green, paler beneath. Sori 

 1-2 to 3-4 of an inch long, oblique to the midrib. Pursh could 

 hardly have been mistaken in this plant, and yet it is singular 

 that it has never been found in our country by any other botan- 

 ist. 



8. PTERIS. Linn. 



Sori in a continuous marginal line. Involucre formed of 

 the inflected margin of the frond, opening inwards. 



1. P. atropiirpurea Linn. : frond pinnate ; lower divisions ternate or 

 pinnate ; segments lanceolate, obtuse, very entire, obliquely truncate 

 or subcordate at base. 



HAB. On rocks. N. Y. to Car. July. L. Fern C 10 inches 

 high. Stipe purple or dark brown, villous. Frond light green 

 on the upper surface, grayish beneath. Sort marginal, conspic- 

 uous. 



9i P. graciiis Mick. : frond pinnate ; pinnae lanceolate, obtuse, al- 

 ternate, sessile, lower ones pinnatifid ; fertile ones entire ; sterile one* 

 crcnate, round-obtuse. Cheilanthcs gracilis Spreng. 



