FILICES. 103 



Carolinianum^ ■isXx.. , B. Virginicum L., Doodia Virginica Presl.) 

 Canada and Florida westward to Michigan and Arkansas. 



§ 3. LORINSERIA Presl. Fronds dimorphous, veins every- 

 where form ijig arcohe. 



3. W. areolata (L.) Moore. Sterile frond with slender 

 stipes, 9' — 12' long, 6'— 8' broad, dtltoid-ovate, with numerous 

 oblong-lanceolate sinuate pinnae ; rachis broadly winged ; fertile 

 frond with an elongate, castaneous stem ; pinnae 3'— 4' long, nar- 

 rowly linear. ( ]V. onocleoides Willd., W. angiistifolia '^m.^Acro- 

 stichum areolatum L.) Maine to Florida, Michigan, Arkansas. 



XVI. ASPLENIUM L. Spleenwort. 



Sori oblong or linear, oblique, separate; indusium straight 

 or rarely curved, opening toward the midrib when single, some- 

 times double. Veins free in all our species. Name from Gr, a, 

 without, and anXj'fv, spleen. A cosmopolitan genus contain- 

 ing nearly 350 species. 



§ I. EUASPLENIUM. Vet'tis free, simple or branched ; indu- 

 sium straight or slightly curved, attached to the upper side of a 

 vein, 



* Fronds simple. 



1. A. serratum L. Fronds growing in a crown from a 

 short, stout, erect rootstock, i|° — 2^° long, 2' — 4' broad, simple, 

 spatulate or linear-oblanceolate, the margin crenulate or irreg- 

 ularly but finely serrate, sub-coriaceous; midrib prominent, 

 keeled and often blackish purple beneath ; veins closely placed, 

 free, once forked ; sori elongate, following the veins of the 

 upper half of the frond from near the midrib half- way to 

 the margin ; indusia single, the free edge entire. Florida. 



** Fronds pinnatifid or pimiate below, tapering to a point. 



2. A. pinnatifidum Nutt. Stipes tufted, 2' — 4' long ; 

 fronds 3' — 6' long, i' — i^' broad, lanceolate, pinnatifid, or pin- 

 nate below, tapering to a slender prolongation above; lobes 

 roundish-ovate, or the lowest pair acuminate; sori numerous. 

 Pennsylvania to Illinois, Kentucky, and Alabama. 



3. A. ebenoides R. R. Scott. Fronds 4' — 9' long, broadly 

 lanceolate, pinnatifid, pinnate below; apex prolonged and 

 slender; divisions Iqnceolate from a bro^d base, the lower ones 



