From Blue to Purple 



What is the advantage gained in the pea-shaped blossom ? 

 As usual, the insect that fertilizes the flower best knows the 

 answer. The corolla has five petals, the upper one called the 

 standard, chiefly a flaunted advertisement; two side wings, or 

 platforms, to alight on; and a keel like a miniature boat, formed 

 by the two lower petals, whose edges meet. In this the pistil, 

 stamens, and nectar are concealed and protected. The pressure 

 of a bee's weight as he alights on the wings, light as it must be, 

 is nevertheless sufficient to depress and open the keel, which is 

 elastically affected by their motion, and so to expose the pollen 

 just where the long-lipped bee must rub off some against his 

 under side as he sucks the nectar. He actually seems to pump the 

 pollen that has fallen into the forward part of the keel upon him- 

 self, as he moves about. As soon as he leaves the flower, the 

 elastic wings resume their former position, thus closing the keel 

 to prevent waste of pollen. Take a sweet pea from the garden, 

 press down its wings with the thumb and forefinger to imitate 

 the action of the bee on them; note how the keel opens to dis- 

 play its treasures, and resumes its customary shape when the 

 pressure is removed. 



The lupine is another of those interesting plants which go to 

 sleep at night. Some members of the genus erect one half of the 

 leaf and droop the other half until it becomes a vertical instead of 

 the horizontal star it is by day. Frequently the leaflets rotate as 

 much as 90° on their own axes. Some lupines fold their leaf- 

 lets, not at night only, but during the day also there is more or less 

 movement in the leaves. Sun dial, a popular name for the wild 

 lupine, has reference to this peculiarity. The leaf of our species 

 shuts downward around its stem, umbrella fashion, or the leaflets 

 are erected to prevent the chilling which comes to horizontal sur- 

 faces by radiation, some scientists think. "That the sleep move- 

 ments of leaves are in some manner of high importance to the 

 plants which exhibit them," says Darwin, "few will dispute who 

 have observed how complex they sometimes are." 



Canadian or Showy Tick-trefoil 



{Meibomia Canadensis) Pea family 

 {Desmodium Canadense of Gray) 



Flo7vers — Pinkish or bluish purple, butterfly-shaped, about ^-in. 

 long, borne in dense, terminal, elongated racemes. Stem ; 

 Erect, hairy, leafy, 2 to 8 ft. high. Leaves: Compounded of 

 3 oblong leaflets, the central one largest; upper leaves nearly 

 seated on stem; bracts, conspicuous before flowering, early 

 falling off. Fruit : A flat pod, about 1 in. long, jointed, and 



