32 THE OSMUNDAS. 
although in reality they are the most essential part of 
the frond. The sterile fronds are broader and blunter 
than those of the cinnamon fern and also lack the little 
tuft of wool at the base of each pinna. 
The fruiting pinne are at first dark ashy-green and at 
a short distance appear almost black, in pleasing contrast 
to the golden-green of the rest of the frond. The spores 
are often ripe before the tips of the fronds have unfurled 
and the parts that bear them soon turn brown and 
wither away. This species frequently presents curious 
transitions between fertile and sterile fronds. Some- 
times all the pinnules on one side of the midrib will be 
fertile and those on the other side, sterile ; or the dilated 
green sterile pinnules will be scattered among the con- 
tracted and brown fertile ones. Occasionally spores are 
borne on the underside of the frond after the manner of 
the polypody and most of our common ferns. 
A strong plant will often bear fifteen fronds, half of 
which are fertile. The sterile spread broadly outward 
but the fertile are nearly erect with only the tips spread- 
ing, making two tiers of green, the taller with a pretty 
palm-like effect. 
In folk-lore, the interrupted fern shares the honours 
with the cinnamon fern, being so near like it. It is 
found from Newfoundland to North Carolina, Missouri 
and Minnesota and is reported to grow in India. From 
the appearance of the fertile frond it was once called 
O. interrupta. Its preference for stony soil is very 
evident. With us it is sometimes called Clayton’s fern. 
The F lowering Fern. 
The flowering fern (Osmunda regalis) is the only 
member of its tribe that is common to both Europe and 
