CHAPTER II. 
THE SHIELD FERNS. 
I. THE HARD PRICKLY SHIELD FERN. 
Polystichum aculeatum. 
''HE Hard, or Common Prickly Shield Fern, 
is one of the grandest and most robust 
of our native ferns, oftentimes reaching a height 
of three or four feet. Evergreen in character, 
its fronds survive the frosts of winter. It has 
a grand root-stock, from the under surface of 
which proceeds a dense mass of long, tough, 
fibrous roots. From its vigorous tufted crown 
this beautiful fern sends up a circle of fronds, 
which grow in shuttlecock fashion, their tips 
gracefully bending outwards. The stem or stipes 
of the Hard Prickly Shield Fern is somewhat 
short, but stiff and rigid, and covered with scales. 
The general outline of the frond is lance-shaped • 
