CRYPTOGAMS. 
263 
occurring in the Eastern and Central United States 
and extending north to Prince Edward’s Island The 
rhizome is collected in early autumn, the fronds cut off, 
leaving the lower portions or stipes attached to the 
rhizomes ; the dead portions of the rhizomes with the 
chaff are removed ; sometimes the stipes are separated 
and the periderm removed. The drug is carefully 
dried and preserved and not kept longer than one or 
two years. 
Description. — Of horizontal or oblique growth, 5 
to 15 cm. long and 1 o 2 - 5 cm thick, mostly covered 
with nearly cylindrical, slightly curved stipe- remnants, 
which are about 25 mm. long and 5 to 10 mm. thick, 
between which is a dense mass of dark-brown, glossy, 
transparent and soft-chaffy scales ; internally spongy, 
pale green, becoming brownish with age; in transverse 
section showing an interrupted circle of about six 
( Dryopteris marginalis ) or seven to ten ( Dryopteris Filix- 
mas) groups of fibrovascular tissue, each of which is 
surrounded by an endodermis-like layer; odor slight, 
taste acrid, somewhat bitter and nauseous. 
Constituents. — Filicic acid 5 to 8 per cent., being 
contained apparently in greatest abundance in rhi- 
zomes collected in autumn, and readily decomposing 
with the formation of filicin, an inactive but crystalline 
anhydride; volatile oil; tannin about 10 per cent.; 
fixed oil about 6 per cent. ; resin, etc. 
Allied Plants. — The rhizome of Dryopteris spinulo- 
sum appears to possess properties similar to the official 
drug; it somewhat resembles that of D. Filix-mas, but 
is distinguished by the chaffy scales possessing mar- 
ginal secretion hairs. 
Adulterants. — The rhizomes of other ferns, as of 
Onoclea sensibilis, are sometimes substituted for those of 
the true drug. 
