Narrow-Leaved Chain-Fern 139 



Venation of sporophylls pinnate, anastomose: paracostal 

 areolae as in sterile leaves, mostly sending out to margin of blade 

 veinlets which either are short with free, almost exsected apices 

 or, especially near nodes of pinnae, prolonged and form a few 

 areolae. 



Sori sausage-shaped, linear or the smaller oblong, each borne 

 on a veinlet forming the outer edge of a paracostal areole and 

 contained in a depression of the leaf: indusia subcoriaceous, at 

 first enwrapping sporongia, the free inner margin somewhat 

 crenulate. 



Spores ovoid-spherical or obscurely spheroid-tetrahedral, ap- 

 parently smooth. 



Habitat. Woodland swamps or damp thickets: usually in 

 shade. In plants exposed to the sun the texture of the leaves 

 becomes thickened and the venation somewhat obscure. Often 

 accompanying Dryopteris simulata. 



Range. Maine to Florida, Louisiana, and Arkansas. Also in 

 Michigan. 



Lorinseria areolata. Presl, Epim. Bot. 72. 1849. 

 Acrostichum areolatum. Linnaeus, Sp. PI. 1069. 1753. 

 Woodwardia areolata (L.). Moore, Index Fil. XLV. 1857. 

 W oodwardia angustijolia. J. E. Smith, Mem. Acad. Roy. Sci. Turin, 5: 

 411. 1793. 



As elsewhere stated,* the plants of Lorinseria areolata, Onoclea 

 sensibilis and Osmundia spectabilis when very young are liable to 

 be mistaken for one another, but can be easily identified. L. 

 areolata and O. sensibilis are closely allied, but bear only the 

 most distant relationship to O. spectabilis. 



In L. areolata the young leaf-blade is at first roundish-cunc- 



* See page 124. 



