162 
ASPIDIACEiE. 
Observation on the genus Polystichum, — Commencing with 
those simple forms of the genus Pohjstichum which are confined 
to the summits of our most bleak and rugged mountains, I have 
traced the figure and cutting of the frond to its most divided 
state, and have raised the latter to the rank of a species, under 
the name of Polystichum angulare^ being as I suppose the As- 
pidium angulare of Willdenow, Sprengel, and Sadler. Thus, 
in the pages immediately following, I have reversed not only the 
sequence observed, but the judgment expressed, in the first edi- 
tion. The latter alteration I consider of doubtful propriety ; it 
is the result of a desire to meet the views of abler botanists than 
myself. This divided form appears to me the concomitant of 
cultivation, the denizen of our established hedge^banks, our 
shady lanes, and our sheltered homesteads. 
