168 THE HUMAN SIDE OF PLANTS 
is these small flowers, hidden underground, which 
insure the propagation of the plant. They are self- 
fertilised, and so are not dependent upon either 
wind or insect for the distribution of the pollen. 
The Polygala is a sociable plant, being, however, 
somewhat clannish, for it usually grows with a 
number of its own kind gathered around it. 
The stem creeps underground, and perhaps this 
has given the Polygala its other name—flowering 
wintergreen—because of the creeping habit, and 
of the resemblance of the leaves to those of the 
real wintergreen. Like the wintergreen, too, it 
loves the deep woods, and is often found nestling at 
the feet of great oak trees, pines, or hickories. 
Tulips, daffodils, crocuses, hyacinths, and nu- 
merous lilies, to say nothing of the common vege- 
tables, such as potatoes, and onions, afford good 
examples of plants whose fruit is hidden safely 
underground. The onion, however, also produces 
seeds above ground. 
Not the least interesting among the ingenious 
methods used by plants in hiding their seeds is 
that followed by certain grasses, such as the Stipa 
pennata, whose auger-like fruits bore themselves 
into the earth by a winding motion, which stops 
only when the seeds are well hidden underground. 
The cyclamen, or, as the old-time botanists called 
