3 
POLYPODIUM DEYOPTEEIS. Lust^^eus. 
( Oah Fern^ or Tender three hranehed Polyjjody.) 
Derfs^ation of Specific Name. From drus^ an oak, pterin, 
a fern. 
syxony:mes. 
POLYSTICHIJM DrYOPTERIS. 
Lastrea Dryopteris. 
Gyi^inocarpiijm Dryopteris. 
DESCRIPTION. 
Caudex, small, wiry, and creeping, mucli branched and 
scaly, with black fibrous rootlets. 
Fronds, of three triangular portions uniting at the top 
of the stalk. Each division is pinnate, with pinnate or 
pinnatifid pinnae. They spring from the points of the 
branches of the caudex, and generally appear in April. In 
exj^osed situations they wither by July or August, but in 
thick woods continue green as late as the end of September. 
Thej" are found both barren and fertile. 
Veins. Midvein waved with alternate simple veinlets 
the ends of which bear the 
Spore Cases which form a circular dark brown cluster 
Roth. 
Rory. 
Newman. 
without cover. 
