40 FERNS AND THEIR ALLIES 



They mature in July and August. The indusia 

 are circular and entire, fixed by the depressed 

 centre, and persistent. 



Var. incisiim {Schwcinitzii). 



This fern is so much like the typical form, 

 growing also in similar situations, that to the 

 untrained eye it would scarcely be distinguished 

 unless closely examined. It is found only occa- 

 sionally, and can always be readily determined 

 by the deeply incised pinnae. 



Its manner of fruiting is also somewhat dif- 

 ferent from the type. Instead of the fruit be- 

 ing wholly confined to the pinnae at the upper 

 portion of the frond, a few fruit-dots may be 

 found on the tips of the lower pinnae, becom- 

 ing less as the base is neared. They mature at 

 the same time as in the type, — in July and 

 August. 



Another variety of the Christmas Fern, cris- 

 pitm, in which the pinnae are ruffled, is also 

 occasionally found. 



BRAUN'S HOLLY FERN. 



Aspidium aculeatum Braunii {Polystichum Braunii). 



Frond twice pinnate, with many pairs of ob- 

 long-lanceolate pinnae ; pinnules oblong, obtuse, 

 short-stalked, sharply toothed, one-sided, and 

 nearly rectangular at the base. The pinnae are 



