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CYSTOPTERIS FRAGIUS, Bern
rS TO P T E R IS Mo:
'O P T E r a S B U L B IF E R A , BerU
Armstrong &.Co.Llt}i.Bciston
F E R N S OF NORTH AM E R IC A . 4 9
P l a t e LIII. — F ig . 1 - 8 .
C Y S T O P T E R IS F R A G IL IS , B e r n h a r d i .
Brittle Fern.
C y s t o p t e r i s f r a g i l i s : — Root-stock elongated, creeping,
covered with persistent stalk-bases, very chaffy towards the
apex with delicate ovate-acuminate ferruginous scales; stalks
slender, brittle, stramineous or bright-brown, a few inches to
a foot long, sparingly chaffy at the base; fronds broadly lanceolate,
thin-membranaceous, smooth, usually bipinnate; pinnæ
oblong-ovate or somewhat deltoid, pointed; pinnules decurrent
on the winged secondary rachis, ovate or ovate-oblong, obtuse,
toothed or variously incised with toothed lobules ; veinlets
pinnately arranged on the midveins, running mostly to the
teeth of the lobes, the lower ones forked, the upper ones
mostly simple; sori small, roundish, seated usually on the
middle of the veinlets nearest the midvein; indusium very
delicate, roundish or ovate, convex, entire or toothed, placed
on the veinlet below the sorus and at first covering it, afterwards
reflexed.
Cystopteris fra g ilis , B e r n h a r d i , in Schraders Neues Journ. f. d. Bot-
anik, i., part !.. p. 27. t. 2, f. 9. — T o r r e y , Flora of New York, ii.,
P- 501- H o o k e r , Sp. Fil., 1., p. 19 7 ; Brit. Ferns, t. 2 3 .—
G r a y , Manual ed. 1., p. 629. etc. — N ew m a n , Hist. Brit. Ferns,
S' ",