22 



POLYPODIACEAE. 



10. ASPLENIUM L. Sp. PI. 1078. 1753. 



Large or small ferns with simple lobed pinnate 2-3-pinnate or pinnatifid leaves, and 

 linear or oblong son oblique to the midribs or rachises. Leaves uniform, or the fer- 

 tile sometimes different from the sterile. Veins free in our species. Indusia straight or 

 curved, opening towards the midribs when single. Sporanges pedicelled, provided with an 

 elastic ring, bursting transversely. [Ancient Greek name ; some species were supposed to 

 be remedies for diseases of the spleen.] 



A genus of some 350 species, of very wide geographic distribution. Besides the following, five 

 others occur in Florida and three in the western parts of the United States. 



Sori straight or rarely slightly curved, attached to the upper side of a vein; leaves mostly small 



(except in No. 7). 

 Leaves pinnatifid or pinnate below, tapering to a point. 



Stipes blackish below; lobes rounded or the lowest acuminate. i. A. pinna tifidum. 



Stipes blackish throughout ; lobes acute or acuminate. 2. A. ebenoides. 



Leaves once pinnate. 



Pinnae 3-12" long, mostly blunt. 



Rachis chestnut-brown or blackish. 



Pinnae auricled at the upper side of the base. 



Pinnae opposite, oblong ; rachis dark brown or black. 

 Pinnae partly alternate, lanceolate ; rachis chestnut-brown. 



4- A 



Pinnae not auricled, partly alternate, partly opposite. 5. A 



Rachis green ; pinnae not auricled. 6. A 



Pinnae 2' -5 long, acute or acuminate. 

 Leaves 2-3-pinnatifid. 



Stipes green ; leaves ovate-deltoid ; pinnules fan-shaped, veins flabellate. 



8. A. Ruta-muraria. 

 Stipes dark at the base, green above. 



Leaves ovate-lanceolate, broadest near the base. 9. A. montanum. 



Leaves lanceolate, broadest above the middle. 10. A. fontannm. 



Stipes chestnut-brown throughout, as also the lower part of the rachis. 



ii. A. Bradleyi. 

 Sori usually more or less curved, sometimes horseshoe-shaped, often crossing to the outer or lower 



side of the veinlet ; large ferns. ( No. 7 may be looked for here. ) 



Leaves 2-pinnatifid : segments blunt, scarcely crenate. 12. A. acrostichoides. 



Leaves 2-pinnate ; pinnules acute, toothed or pinnatifid. 13. A. Filix-foemina. 



3. A. parvuhim. 



platyneuron. 

 Tricliomanes. 

 i' i ride. 

 A. august if olium. 



i. Asplenium pinnatifidum Xutt. Pinnatifid Spleenwort. (Fig. 46.) 



Asplenium pinnatifidum Nutt. Gen. 2 : 251. 

 1818. 



Rootstock short, creeping, branched, 

 chaff}-. Stipes tufted, polished, blackish be- 

 low, green above, 2' '-5' long, somewhat 

 chaff}- below, at least when young; leaves 

 broadly lanceolate in outline, s'-io' long, 

 firm, tapering upward to a long narrow 

 point, pinnatifid or the lower parts pinnate ; 

 lowest pinnae or occasionally several pairs 

 sometimes tapering to a point like that of 

 the apex of the leaf; lobes or pinnae rounded 

 or the lowest acuminate ; sori commonly 

 numerous, straight or slightly curved. 



On rocks. New Jersey and Pennsylvania to 

 Illinois, south to Georgia. Alabama and Arkan- 

 sas. Ascends to 3000 ft. in North Carolina. The 

 end of the long tip of the leaf sometimes takes 

 root as in the Walking-fern. July-Oct. 



