PRnilPVI FERTILE AND STERILE FRONDS LEAF- LIKE 

 UKUUr VI AND USUALLY SIMILAR; fRUIT-DOTS ROUND 



way of holding itself. Sometimes the fronds stand 

 three feet high, and are broad and spreading. Again, 

 they are tall, slender, and somewhat erect. Again, 

 they are not more than a foot high. 



At its best it grows with almost tropical luxuri- 

 ance and is a plant of rare beauty, its fronds hav- 

 ing a certain featheriness of aspect uncommon in 

 the Aspidiums. 



Var. dilatatum {D. spinulosa dilatatd) 



Newfoundland to North Carolina, chiefly in the mountains. 



Fronds. — Usually large, broader at base than in either of the pre- 

 ceding species, ovate or triangular-ovate, oftenest thrice-pinnate ; 

 pinnules lance-oblong, the lowest often much elongated ; fruit- 

 dots round ; indusium smooth. 



This form of the Spinulose Wood Fern is distin- 

 guished chiefly by its broader fronds and by the 

 smooth indusia. As these indusia can be seen satis- 

 factorily only by the aid of a magnifying-glass, there 

 is frequently some difficulty in distinguishing this 

 variety. Occasionally it occurs in a dwarf state, 

 fruiting when only a few inches high, 



41. BOOTT'S SHIELD FERN 



Aspidium Booitii {Dryopteris Boot Hi) 



Nova Scotia to Maryland, about ponds and in wet places. 

 One and a half to more than three feet high, with somewhat chaffy 

 stalks which have pale-brown scales. 



Fronds. — Long lance-shaped, somewhat narrowed at base, nearly 

 or quite twice-pinnate; pinna, the lowest triangular-ovate, upper 

 longer and narrower ; pinnules oblong-ovate, sharply thorny- 

 toothed, somewhat pinnatifid below ; fruit-dots round ; indusium 

 slightly glandular. 



168 



