FERN FAMILY 63 



really sensitive, withering very quickly when 

 picked. 



In some sections of New England this fern is 

 wrongly called the " Polypod," or " Polj'pod 

 brake," although it bears no resemblance to 

 that species. There is quite a similarity in form 

 to the Net-veined Chain Fern, but the divisions 

 in the sterile frond of the Sensitive Fern are 

 not minutely toothed as in the Net-veined Chain 

 Fern, hence can be identified readily before the 

 fertile fronds appear. These are usually few, 

 and do not appear until June. 



They are twice pinnate and much contracted. 

 The pinnules are so rolled as to become berry- 

 shaped and inclose the fruit, which matures in 

 July and August. The indusium is hood-shaped 

 and very delicate. 



The fertile fronds bear some resemblance to 

 the fruit of the Grape Ferns — Boiijchimn — 

 but are heavier. They remain erect during the 

 winter and frequently persist a year or two. 



Forma obtusilobata is an intermediate form 

 between the fertile and non-fertile fronds. It 

 is found occasionally with the type. 



DICKSONIA. 



This genus was named for James Dickson, an 

 English botanist, 1 738-1 822. 



