GENERA AND SPECIES. 87 
PLATE XXX. 
ASPIDIUM THELYPTERIS. Swartz. 
MARSH SHIELD FERN. 
The usual habitat of this fern is in swamps and boggy 
marshes, choosing for its companions the Sensitive Fern, 
the Osmundas, and the cryptogamic and flowering plants 
peculiar to marshy ground, such as the Sagittaria, Lizard’s 
Tail, Cat-tail Flag, Equisetum, etc. The plant has a beau- 
tiful fresh green color, the dark green of the upper side of 
the fronds contrasting very strongly with the light green 
of the back, occasioned by the profusion of light-colored 
fruit-patches. It comes to maturity about the latter part 
of July or the first of August. The frond is pinnate -lan- 
ceolate, pinne deeply pinnatifid; the margins of the lobes 
are revolute. 
It is not very common in Kentucky. The best speci- 
mens I have obtained were from a marsh near Prospect, 
on the Narrow Gauge Railroad, about ten miles from 
Louisville. The Plate represents a piece of a frond natural 
size. 
