76 



Rhodora 



[April 



becoming chaffy along the strongly grooved and winged rachises ; 

 fibro-vascular bundles 3-5 or 7. Laminae 10-20 or more inches 

 long, 6-10 inches broad, oblong or ovate lanceolate, or triangular- 

 ovate with long acuminate apices, broadest just below the middle, 

 bipinnate or, in the largest forms, tripinnate, at least below ; pinnae 

 mostly ovate or oblong lanceolate, long-acuminate, the lowermost pair 

 much the broadest and irregularly deltoid, the superior pinnules much 

 the ^longest, lobes irregularly spinulose or sharply toothed ; texture 

 subcoriaceous, softly downy in the young fronds, and wrinkled on 

 the face from the deep furrows of the midribs and veins ; sori ele- 

 vated, submarginal, reniform, indusia coriaceous ; veins pinnately 

 branched and forked. 



Syn. Nephrodium Pittsfordense Davenport, in litt. 

 The special characters of this plant lie in the long-acuminated out- 

 line of the fronds and pinnae, the submarginal elevated sori and cori- 

 aceous indusia, and the occa- 

 sional presence on the older 

 stipes of large deeply lobed 

 or lacerated appressed scales 

 with a broad dark base and 

 the exterior lobe greatly 

 elongated. The scales of 

 the stipes are for the most 

 part attached at the base by 

 a well rounded sinus with 

 either entire or ciliated mar- 

 gins ; the smaller ones much 

 like those on some of the 

 Polypodiums, as for example, 

 P. polypodioides. 



In the subcoriaceous tex- 

 ture, and to some extent in the 

 coloring, of the fronds, and 

 in the conspicuous submar- 

 1 ginal elevated sori appearing 

 almost cork-like in age, the 

 plant resembles D. tnargina- 

 //s. The toothed margins of 

 the fronds, on the other hand, 

 suggest P>. spinulosa. Both 

 at first sight and on close examination the hybrid character of the 

 plant appears unquestionable. 



