ONOCLEA STRUTHIOPTERIS, Hoffmann. 
Ostrich-Fern. 
Onoclea Struthiopteris : — Caudex short, thick, erect, 
emitting slender subterranean stolons; stalks stout, a few 
inches to a foot long, chaffy at the base; fronds standing in 
a vase-like crown, dimorphous; sterile ones one to ten feet 
high, herbaceo-membranaceous, broadly lanceolate, narrowed 
from the middle to the base, abruptly short-acuminate, pinnate; 
pinnae very many, sessile, the lowest ones sinuate and deflexed, 
the rest three to eight inches long, five to nine lines wide, 
linear-lanceolate, acuminate, deeply pinnatifid into numerous 
close-placed oblong obtuse entire segments provided with a 
midvein and several simple veinlets on each side ; fertile 
fronds in the middle of the crown or vase, much shorter 
than the sterile, rigid, contracted, narrowed at the base, pin- 
nate; pinnae one to two inches long, crowded, obliquely 
ascending, linear, obtuse, sub-entire or pinnately lobed, the lobes 
one or two lines long and broad, the margins much recurved, 
and the whole pinna forming a somewhat articulated pod-like 
body ; veinlets of the fertile segments few, soriferous on the 
back; receptacle elevated; indusium very delicate, lacerate- 
toothed, half surrounding the sorus; sporangia at length con- 
fluent and filling the fertile pinnae. 
