﻿THE FERN BULLETIN 



99 



there are at least six ferns which intercross, namely, D. 

 cristata, D. clintoniana, D. goldieana, D. maginalis, 

 D. spinulosa and D. spinulosa intermedia. Mr. Bene- 

 dict has pointed out that there are fifteen combinations 

 possible here. Of these we already have the following: 

 D. cristata x marginalis, Davenport ; D. cristata x 

 spinulosa intermedia Powell * = D. Boottii; D. clin- 

 toniana x goldieana Dowell * " : D. goldieana celsa 

 Palmer; D. clintoniana x marginalise D. clintoniana x 

 spinulosa intermedia, Dowell ; * D. goldieana. x mar- 

 ginalis, Dowell * ; D. goldieana x spinulosa interme- 

 dia Dowell *; and D. marginalis x spinulosa — D. 

 Pittsfordensis, Slosson f ; D. cristata x spinulosa 

 is known to occur both in this country and in Europe. * 

 Four of the six remaining members, of the group were 

 exhibited by Mr. Benedict at the meeting of the Torrey 

 Club already mentioned, and will soon be published. 

 This leaves two yet to be found. I confidently assume 

 that they exist, and am convinced that collectors have 

 only to look, to find, perhaps neglected in their own 

 herbaria, both these and many other examples of hy- 

 bridity in our native ferns. 

 Pittsford, Vt. 



THE GRASS -LIKE POLYPODIUM. 



Poly pod hi m gr amine u m . 



By Willard N. Clute. 



In the popular mind finely-cut foliage and ferns are 

 indissolubly connected. To such, the leaves of yarrow 

 and columbine always have ferny characteristics and 

 the adjective fern-like is always understood to refer 

 to a much-divided leaf. The further one extends his 

 knowledge, however, the less the word fern-like repre- 



* Bull.Torrey Club, 35: 135; 1908. 



f Rhodora, 6: 75; 1904. 



t Bull.Torrey Club, 35: 135t 1908. 



