THE WOOD FERNS. 148 
swamp, though it may be found along streams, in moist 
thickets and occasionally in the open ground. 
A form principally distinguished by its much larger 
and broader fronds is known asthe variety Clintontanum. 
It is found in rich wet woods in America but has not 
been reported from the Old World. It may sometimes 
be mistaken for Goldieanum but is easily distinguished 
by its broad triangular lower pinne. 
Mr. Davenport has recently described a curious plant 
with characteristics intermediate between this species and 
marginale which he calls A. cristatum X marginale. He 
considers it a hybrid and describes it as having the upper 
part of the frond like marginale and the lower third like 
cristatum, with veining and texture like the latter. The 
rootstock is erect and the frond is very prone to vary and 
to produce abortive and misshapen fronds. The sori are 
borne near the margin of the pinnules and the indusium 
is convex as in marginale. Thus far it has been found 
in various places in all the New England States and 
in New Jersey. 
Aspidium cristatum Clintonianum, Middle pinna. 
Aspidium Boottit. 
In appearance Aspidium Boottit stands half way be- 
tween the crested and the spinulose shield ferns and is 
sometimes thought to be ahybrid betweenthem. It has 
