CRYPTOGAMIA, FILICES. 
211 
A. polypodoides, Swartz. 
A. trichomanoides, Mich. 
Acrostichum platy neuron, Sp. PI. 1527, excluding 
the synonym. 
Icon. Schk. filic. t. 73. Pluk. aim* t. 287. f. 
2. et t. 89. f. 8. 
Ebony Spleen-wort. 
A beautiful species, from six to twelve inches high, stem 
deep shining black. On the rocks bordering the Schuylkill, 
in rich shady woods, and on the grassy borders of copses ; 
common. Perennial. July. 
tl. A. fronds pinnate; pinnse suhrotund, obtuse, mdanocau^ 
crenate, ciineate at the base; stipe discoloured. 
i — Willd. enum. 
A. trichomanes, Mich. 
A small and beautiful species, with a very polished black 
stem. With No. 2, common. Perennial. July. 
4. A. fronds bi-pinnate at the base, simply pin- 
nate at the top ; pinnulae rhomboid-oblong, ob- 
tuse ; apex obtuse, denticulate. — Willd. 
Icon. Schk. lilic. t. 80. b. FI. Dan. 190. 
A very small species, from one to three inches high. Ex- 
ceedingly rare, and scarce when found. In the crevices of 
the highest rocks on the Wissahickon. Perennial. July. 
394. PTERIS. Gen. pi. 1626. 
Sori continuous, linear, marginal. Indusium 
from the inflected margin of the frond, 
opening inwards. — dSTutt. 
1, P. fi ond pinnate, three-parted, barren j branch- aquiUna. 
es bi-pinnate; pinnse linear-lanceolate, obtuse, 
pinnatifid-dentate; fructificatory ones pinnate; 
