1 2 Rhodora [January 



The character of the fibro-vascular bundles is the same as in all 

 \ members of the group to which this plant belongs. 



I doubt if it is possible to formulate any absolute rule for deter- 

 mining the different species and varieties of the evergreen shield ferns 

 from the character of the vascular bundles,-— Certainly not from their 

 number, which is regulated by the size of the frond and the stout- 

 ness of the stipe. Thus in large fronds of the different species the 

 number may be seven, and in small fronds five, or even three, at the 

 base of the stipe, with corresponding reductions above. 



Our plant is no exception to this rule, but it has shown such re- 

 markable variations from all other forms of the group that it seems 

 worthy of special notice. 



Several seasons' observations have left me as much in the dark as 

 to its origin as at first. 



That it is a hybrid I believe, but between what ferns it is impossi- 

 ble to say. Marginal* characters appear in the sub-erect crowns, and 

 in the sometimes nearly marginal elevated coriaceous sori ; C/iti/oni- 

 anum characters in the decumbent lateral crown and medial sori ; 

 Spinulosu?n characters in the sometimes deltoid lower pinnae, elon- 

 gated pinnules, and sharply, almost spinulosely toothed lobes. 



As just such another plant may never be found again it does not 

 seem worth while to dignify this one with a name, but in case another 

 should be found the following diagnosis may assist in determining 

 it more clearly. 



Mature sporophyte large (12 to 24, or more inches tall), partially 

 evergreen, sterile fronds persistent, sporophylls gradually withering 

 away ; rootstock decumbent, fasciculate, original crown sub-erect 

 increasing laterally, at length forming large composite clumps, with 

 sub-erect, decumbent or lateral, crowns all connected by short, stout 

 rhizomes, combining types of marginal* and Clintomanum\ crosiers 

 densely clothed with a mixture of large ovate and narrowly lanceolate 

 pale brown scales. Stipes usually 4 to 8 inches long, sometimes 

 longer, and, as well as the primary rachis, stramineous, often darker 

 below, deeply channelled along the face, clothed at the base, and well 

 above, with the ascending scales from the crosiers, and chaffy along 

 the upper rachises. Laminae 12 to 18 inches, or more, in length, 4 to 

 10 inches broad in the middle, narrowing both ways, often abruptly 

 so at the acuminate apex, which then resembles that of A r . mar- 

 gin a le ; once or twice pinnate, or thrice pinnatifid ; the middle pinnae 



