236 THE FAIRY-LAND OF SCIENCE. 
anywhere all through the summer, and you will know 
it from other flowers very like it by its leaf, which is 
not a true trefoil, for behind the three usual leaflets 
of the clover and the shamrock leaf, it has two small 
leaflets near the stalk. The flower, you will notice, 
is shaped very like the flower of a pea, and indeed it 
belongs to the same family, called the Papilionacea? or 
butterfly family, because the flowers look something 
like an insect flying. 
In all these flowers the top petal (sta, Fig. 66) 
stands up like a flag to catch the eye of the insect, 
and for this reason botanists call it the " standard." 
Below it are two side-petals w called the " wings," and 
if you pick these off you will find that the remaining 
two petals k are joined together at the tip in a shape 
like the keel of a boat (2, Fig. 66). For this reason 
they are called the " keel." Notice as we pass that 
these two last petals have in them a curious little 
hollow or depression d, and if you look inside the 
" wings " you will notice a little knob that fits into 
this hollow, and so locks the two together. We shall 
see by-and-by that this is important. 
Next let us look at the half-flower when it is cut 
open, and see what there is inside. There are ten 
stamens in all, inclosed with the stigma in the keel ; 
nine are joined together and one is by itself. The 
anthers of five of these stamens burst open while the 
flower is still a bud, but the other stamens go on grow- 
ing, and push the pollen-dust, which is very moist 
and sticky, right up into the tip of the keel. Here 
you see it lies right round the stigma s, but as we 
saw before in the geranium, the stigma is not ripe 
