418 CLASS XXIV. ORDER I. 



three branches, which are spreading and sonriewhat reflexed. 

 Each of these is pinnate, the divisions pinnate or pinnatifid, with 

 the larger segments crenate. Fructification is very small, dis- 

 tinct dots. — Near Hanover, New Hampshire. 



426. WOODSIA. 



WooDsiA iLVENsis. Pursh 1 Hairy Woodsia. 



Fronds pinnate ; divisions pinnatifid ; segments 

 obtuse; fructification near the margin, at length con- 

 fluent ; stipe villous. 

 Syn. PoLTPODiUM ilvense. Willd. 



This little plant is the Polypodium ilvense of Muhlenberg's 

 catalogue, but seems somewhat different from the plant of Browu 

 and Pursh. Stipe from three to six inches high, chaffy below, 

 villous and woolly above. Frond pinnate, woolly underneath, 

 the margin covered with fructification. Barren rocks and dry 

 woods. 



427. ASPIDIUM. 



AsPiDiuM AcROSTicHoiDEs. Muhl. Terminal SJticld Fern. 



Stipe chaffy ; frond long, pinnate, its divisions 

 alternate, subsessile, auriculated on one side at base, 

 slightly serrate, ciliate; only the upper ones fruitful. 

 Mich. sub. syii. 

 Syn. Nephrodium AcpvOstichoides. Mich. 



Remarkable for the difference between its lower and upper 

 leaves. The stipe is covered with loose, membranous, chaffy 

 scales. The leaves or pinnae are numerous, oblong, somewhat 

 acute, edged with small, mucronate serratures, furnished with 

 an angular lobe on their upper side at base. The lower leaves 

 are without fruit ; the upper ones much smaller, covered with 

 dots of fructification, which unite, so as to overrun the whole 

 under surface. — Rocks and hills, Roxbury. — Perennial. 



AsPiDiuM NovEBORACENSE. *S^/«. New York Shield Fern. 



Frond pinnate ; divisions linear-lanceolate, pinna- 



