268 The Romance of Wild Flowers 
Butterwort (Pinguicula vulgaris) is a_ small 
perennial growing in bogs, the succulent oblong 
leaves forming a rosette close pressed to the ground, 
from amid which the one-flowered scapes rise to a 
height of five or six inches. The violet flower is 
two-lipped, with a slender spur. There are only two 
perfect stamens, and these are attached to the base 
of the corolla-tube. The style is short and thick, 
with an unequally two-lipped stigma. The most 
interesting feature of the plant is its leaves, which 
are about 1} inch long, and covered on the upper 
side with glandular hairs which secrete a sticky, 
colourless fluid, capable of being drawn out into 
threads a foot and a half long after the leaf has 
been excited. This secretion has long been noticed, 
and the names Butterwort and Pinguicula (from 
pinguis, grease) have been suggested by it. But 
the ancients knew nothing of its importance to the 
plant, which indeed was not suspected until Mr. W. 
Marshall told the late Charles Darwin that he had 
noticed the plant as growing in the mountains of 
Cumberland with many 
insects adhering to the 
leaves. This led the 
great naturalist to in- 
vestigate the reasons 
for their presence, and 
the behaviour of the 
leaves. He found that 
dead insects and other 
nitrogenous substances 
excite the glands to increased secretion of the viscid 
fluid, which then becomes acid, and capable of 
Section of Butterwort 
