CHAPTER XII 
SieVERY SPLUEENWORTE 
Athyrium thelypteroides. 
Rootstock creeping, forking, brown, green at tips, bearing 
delicate, pale-brown, lanceolate or ovate-lanceolate or ovate- 
deltoid, acuminate, slightly toothed or ciliate scales: roots 
brown, coarse, copiously branching, springing from rootstock 
and junctures of petiole and rootstock. 
Leaves twenty to forty-seven inches long, five to twelve inches 
broad, sensitive to frost. 
Petioles eight to twelve inches long, shorter than blades; at 
base dark-brown or at first partly green, turgid-compressed, 
angled laterally and toothed along angles; above greenish- 
straw-colored or straw-colored or brownish when dried, furrowed 
on face; somewhat scaly and pubescent: scales pale-brown, 
broadly ovate to lanceolate to linear, acuminate, entire, the 
linear often, at least the upper, articulated at apex: hairs articu- 
lated, marked at joints and sometimes lengthwise in brown or 
golden-brown: fibrovascular bundles two, strap-shaped, uniting 
below blade into one somewhat U-shaped in section. 
Blades lanceolate or ovate-lanceolate, gradually or abruptly 
narrowed toward apex, somewhat narrowed at base, pinnate, 
pinnatifid toward apex: apex acuminate, undulate to serrulate 
