THE MARSH FERN TRIBE. 125 



to the place in which it grows ; for while Thelypteris loves 

 the sunny swamps and Noveboracense, dryish shades, the 

 present species demands the moisture of the one and 

 the shade of the other and is to be found in deep wet 

 woodlands. 



The rootstock, as might be inferred, creeps near the 

 surface of the soil and sends up bipinnatifid fronds which 

 are like those of Thelypteris in general appearance but 

 like those of Noveboracense in colour, texture and the 

 graceful curve of the blades. In technical language they 

 may be described as lanceolate, acuminate, pinnate with 

 numerous sessile, lanceolate, long-pointed, pinnatifid 

 pinnae and narrow obtuse segments. 



In the vicinity of New York, the fertile fronds appear 



FRUITING PINNA. 



in July. They are slightly taller and more erect than 

 the sterile and bear the medium-sized sori in a double 

 row on the pinnules. The indusia are thin and rather 

 more conspicuous than those of its nearest relatives. 

 Although the frond may be heavily fruited, the pinnules 

 appear never to become revolute as in Thelypteris. 



When seen growing in masses this fern seems almost 

 identical with Noveboracense but single fronds show a 

 very decided difference. While the lower pinnae may be 

 slightly smaller than those in the middle of the frond, 

 they are never so greatly reduced as in Noveboracense. 

 The stipes are also much longer. The marks by which it 

 may be distinguished from Thelypteris are the flat fertile 



