GENERA AND SPECIES. 69 
PLATES XX AND XXI. 
ASPLENIUM ANGUSTIFOLIUM. Michx. 
NARROW-LEAVED SPLEENWORT. 
This fern differs from any of the Aspleniums yet de- 
scribed, both in general appearance and habitat. It loves 
the damp, rich soil of deeply shaded woods, and has for its 
companions the true Maiden-hair Fern, the Beech Fern, 
and the Lady Fefn. It is a tall and graceful plant, often 
growing four feet in height. It has two kinds of fronds, 
the sterile and fertile. The sterile frond (Plate XX) is 
pinnate with lanceolate pinne, broad at the base. It is 
very soft and delicate, and when fully grown is about two 
feet high. The fertile frond (Plate XXI) comes up much 
later, and is also pinnate, the pinne contracted and narrow, 
the upper side being somewhat ribbed, and the lower pro- 
fusely covered with fruit-patches arranged in pairs on each 
side of the mid-vein. The frond is tall and linear, having 
the appearance of a willow wand. The two illustrations 
show the fronds cut off near the point, and are sufficient 
to enable the young student to determine the plant. 
The Narrow-leaved Spleenwort is a very tender fern, 
nipped by the first frosts. In July and August it is most 
luxuriant; accordingly, it is sometimes called the Summer 
Fern. It is very common in all our damp, rich woods. It 
grows quite readily on sheltered mounds with plenty of 
rich soil. 
