F1LICES. 103 



CaroItnianumViiAt., B. Virginicum L., Doodia Virginica Presl.) 

 Canada and Florida westward to Michigan and Arkansas. 



3. LORINSERIA Presl. Fronds dimorphous, veins every- 

 where forming areolte. 



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. ( W. onocleoides Willd., IV. angustifolia Sm. , 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 ovr/l?/*' , spleen. A cosmopolitan genus contain- 

 ing nearly 350 species. 



I. EUASPLENIUM. Veins 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 pinnate 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. 



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

 lanceolate, pinnatifid, pinnate below ; apex prolonged and 

 slender; divisions lanceolate from a broad ba.se, the lower ones 



