—87— 



Veins copiously anastomosing. 

 Indusium normally absent. 



Leaves bipartite, the main vein dichotomous 



Diptcris Reinw. 



Leaves pinnate Dictyopteris Presl. 



Indusium orbicular, centrally peltate. 



Areolae regular, with the included veinlets straight and 

 directed towards the margins of the segments. 



Cyrtomiuni Presl. 



Areolae irregular, fine, the included veinlets often 



branched and recurrent Tectaria Cav. 



Indusium cordato-reniform, attached by the sinus. 



Sagenia Presl. 



A NEW FORM OF THE BOULDER FERN. 



By YVillard X. Clute. 



W hile collecting plants last year at Andover, Conn., Mr. A. 

 Vincent Osmun found a plant of Dicksenia pilosiuscula with 

 all its fronds unlike those from normal plants. These fronds, 

 about ten in number, were taken and later in the season, six 

 more were secured. Some of these Mr. Osmun has recently sent 

 me for identification, and as they appear to possess characters 

 somewhat different from ordinary fronds, I think they deserve 

 a separate name. The principal difference is found in the cutting 

 of the frond, which is analogous to that exhibited by Asplenium 

 cbcncum f. serration, or Botrychium obUquum f. dissectum. In 

 the present case the cutting between the teeth of the pinnules is 

 very deep, each terminal veinlet being bordered by a narrow green 

 wing of tissue for most of its length. I would describe it as fol- 

 lows : 



Dicksonia pilosiuscula. forma Schizophylla. Rootstock 

 and stipe similar to the type. Fronds 6-22 inches in length ; blade 

 rather narrow, pinnae unequal in length, teeth of the ultimate 

 pinnules very deeply cut. each vein forming the midrib of a nar- 

 row tongue-like segment. Collected at Andover, Conn.. July 27. 

 1901. by A. Vincent Osmun. Type in my own herbarium. 



The boulder fern is noted for the handsome cutting of its 

 fronds, and this new form, carrying the cutting still further, 

 makes a plant very desirable for cultivation. It is to be hoped 



