42 RATTLESNAKE FERN AND ADDER’S-TONGUE. 
the terrifying name of the rattlesnake fern (Botrychium 
Virginianum). It isa woodland species but by no means 
to be charged with harbouring the venomous serpent for 
which it is named. It delights in dim moist hollows, 
and is quite impatient of the sun, soon disappearing from 
a locality when the protecting trees are removed. 
In southern New York, the single fronds of this species 
begin to push up about the last week in April. Unlike 
higher types of ferns, they are folded rather than coiled 
in the bud and come out of the earth almost erect. 
Many suppose that each plant has two fronds, a fertile 
and sterile, but this isa mistake. There is but a single 
frond divided into a fertile and sterile portion. The 
sterile half expands soon after it appears above ground 
but the fertile is most deliberate and requires fully a 
month longer to mature. In June the spores are pro- 
duced and then, having fulfilled its mission, the fruiting 
part begins to wither. It often disappears by July, al- 
though vestiges of it may be found on the frond all 
summer. 
This species is often three feet high and when full grown 
is a handsome plant. The sterile blade, borne some dis- 
tance above the earth by the fleshy stipe, 
‘i spreads horizontally in a broad flat triangle, 
aye and above it the fertile portion rises several 
if inches. The blade is usually described as ter- 
nate, but it is easily seen that two of the 
three divisions are really the enlarged lower 
pair of pinne. Calling these pinnz, the frond 
is quadripinnate ; or tripinnate with pinnatifid 
pinne below, and once or twice pinnate with 
pinnatifid pinne above. The segments are about ovate 
in outline. The fertile part is two or three times pin- 
mo 
SPORANGIA. 
