FILICES. 177 



those of the fertile fronds narrower than those of the sterile 

 ones. Stipe polished, brownish, darker at the base. Shady 

 limestone rocks ; not common. 



2. P. atropurpu'rea, Link. Larger than the last, 6-15 

 inches high, the stipe dark-purple and, shining. Frond pale, 

 once- or (below) twice-pinnate, the divisions broadly linear 01 

 oblong (or the sterile sometimes oval), stalked at the base. 

 Stipes clustered. Dry rocks. 



5. ASPI/E'NTUM, L. SPLEENWORT. 



1. A. Trichom'anes, L. A very delicate little fern growing 

 in tufts on shaded cliffs. Fronds 3-6 inches long, linear in outline, 

 pinnate, the little pinnae oval and unequal-sided, about ^ of an 

 inch long. The stipes thread-like, purplish-brown and shining. 

 This species is evergreen. 



2. A. thelypteroi'des, Michx. Fronds 2-3 feet high, pinnate, 

 the pinnae linear-lanceolate in outline, 3-5 inches long, deeply 

 pinnatifid, each of the crowded lobes bearing 3-6 pairs of oblong 

 fruit-dots. Rich woods. 



3. A. angUStifo'lium, Michx. Fronds simply pinnate, some- 

 what resembling Aspidium acrostichoides, but vert/ smooth and 

 thin, and larger. Pinnae crenulate, short-stalked. Fruit-dots 

 linear, crowded. Rich woods ; not common. 



4. A, Filix-fce'mina, Bernh. Fronds 1-3 feet high, broadly 

 lanceolate in outline, twice-pinnate, the pinnae lanceolate in outline, 

 and the pinnules confluent by a narrow margin on the rhachis of 

 the pinna, doubly serrate. Jndusium curved, often shaped some- 

 thing like a horse-shoe, owing to its crossing the vein and becoming 

 attached to both sides of it. Rich woods. 



6. WOODWARD'IA, Smith. CHAIN FERN. 

 W. Virgin'ica, Smith. Fronds 2-3 feet high, pinnate ; pinnae 

 lanceolate, pinnatifid. Veins forming a single row of meshes 

 next the midrib. Wet swamps. 



7. SCOLOPEN'DRIUM, Smith. HABT'S TONGUE. 



5. Vlllga're, Smith. Frond simple, bright green, a foot or 

 more in length, and an inch or more in width. Shaded ravines 

 and limestone cliffs ; not \ ery common. 



