FILICES. (FERNS.) 683 



to the midrib, confluent when ripe and covering the under surface of the now 

 fully opened segments ; sterile fronds on much shorter stipes, with ovate or 

 obovate decurrent and crenately toothed or incised segments. (Allosorus 

 acrostichoides, Sprengel.) On rocks, from L. Superior westward and north- 

 ward. Very near C. crispa of Eu. 



8. WOODWABDIA, Smith. CHAIN-FERN. (PL 17.) 

 Fruit-dots oblong or linear, arranged in one or more chain-like rows on trans- 

 verse anastomosing veinlets parallel and near to the midrib. Indusium fixed 

 by its outer margin to the fruitful veinlet, free and opening on the side next 

 the midrib. Veins more or less reticulated, free toward the margin of the 

 frond. Large ferns, with pinnatifid or pinnate fronds. (Named for Thomas 

 J. Woodward, an English botanist.) 



1. ANCHfSTEA. Sterile and fertile fronds alike; veins forming only one 

 row of meshes (areoles). 



1. W. Virginica, Smith. (PL 17, fig. 4, 5.) Fronds (2-3 high) pin- 

 nate, with numerous lanceolate pinnatifid pinnae; segments oblong; veins 

 forming a row of narrow areoles along the midrib both of the pinnae and of 

 the lobes, the outer veinlets free ; fruit-dots oblong, one to each areole, con- 

 fluent when ripe. Wet swamps, Maine to Ark., and southward. Rootstocks 

 creeping, often 6-8 long ! July. 



2. LORINSllJRIA. Sterile and fertile fronds unlike ; veins of the sterile 

 fronds forming many rows of meshes. 



2. W. angUStif61ia, Smith. (PL 17, fig. 1-3.) Fronds pinnatifid; 

 sterile ones (12 - IS' high) with lanceolate serrulate divisions united by a broad 

 wing ; fertile fronds taller, with narrowly linear almost disconnected divisions, 

 the areoles and fruit-dots (4 - 5" long) in a single row each side of the second- 

 ary midribs ; rootstocks creeping. Wet woods, New Eng., near the coast, to 

 Ark., and southward ; rare. Aug., Sept. 



9. ASPLENIUM, L. SPLEENWORT. (PL 18.) 

 Fruit-dots oblong or linear, oblique, separate ; the straight, or rarely curved, 

 indusium fixed lengthwise by one edge to the upper (inner) side of the fertile 

 vein ; in some species a part of the fruit-dots are double, the fertile vein bear- 

 ing two indusia placed back to back. Veins free in all our species. (Name 

 from a- privative and ffirX^v, the spleen, for supposed remedial properties.) 

 1. ASPLENIUM proper. Indusium straight or slightly curved, attached to 



the upper side of the vein, rarely double. 



* Small evergreen ferns ; fronds pinnatifid, or pinnate only near the base. 

 1. A. pinnatifidum, Nutt. Fronds (3 - 6' long) lanceolate, pinnatifid, 

 or pinnate below, tapering above into a slender prolongation, " the apex sometimes 

 rooting " ; lobes roundish-ovate, obtuse, or the lowest pair long-acuminate ; fruit- 

 dots irregular, those next the midrib often double, even the slender prolonga- 

 tion fertile. On cliffs and rocks, Penn. to Mo., and southward ; very rare. 

 July. Resembles the Walking-Leaf (Camptosorus), but the veins are free. 

 Stipes brownish, becoming green above, and so passing into the broad pale green 

 midrib. 



