52 FERNS AND THEIR ALLIES 



difference in form is frequently more marked at 

 the tips than elsewhere. Compare the illustra- 

 tions. 



The Cinnamon Fern grows in swamps or wet 

 places, in large bunches, and is very common. 

 The sterile fronds appear a trifle later than the 

 fertile ones, and grow taller, sometimes from 

 three to five feet high. They are clothed with 

 rusty wool when young. Occasional forms oc- 

 cur with the type. 



The fertile fronds are few, from one to two 

 feet high, erect, and in the centre of the crown 

 at maturity. They are twice pinnate, contracted, 

 and covered with sporangia which are at first a 

 bright green, but later become cinnamon-colored 

 and soon wither, leaving the sterile fronds to 

 mature later. The fertile fronds usually mature 

 in May or early in June. 



The pinnae of the sterile fronds of the Cin- 

 namon Fern wither with the early frosts and fall 

 from the rachides, leaving the crown of naked 

 stems to stand somewhat erect during the 

 winter, unless lodged by the weight of snow. 



INTERRUPTED FERN. 



Osmunda Claytoniana. 



Sterile fronds pinnate ; pinnse deeply pinnati- 

 fid, with broad, oblong, obtuse, and entire lobes, 

 which are more blunt than those of the Cinna- 



