124 



THE LOCUST TREE. 



closes ; Sd, the whole leaf falls backward and downward 

 by the joint at the base of the petiole.* 



The Name, RoUnia, was conferred in honor of John 

 Eobin, herbalist to Henry IV. of France, A. D. 1620. By 

 his son the Locnst was first cultivated in Europe in 



5, Mimosa pudica ; 6, Desmodium gyrans. 



1640, under the popular name Acacia ; hence its specific 

 name, R. pseiidacacia (False Acacia). Two other species are 

 native in southern forests and often seen in cultivation. 

 (See Bot. S Flor.,^. 96.) 



* The Moving Plant {Desmbdiiim gyrans) is another member of this great Order. 

 It is native in India along the Ganges. In this country it is cultivated in the green- 

 house. The leaves are pinnately trifoliate, consisting of a pair of very small leaflets 

 placed a little below the large terminal oblong leaflet. These are wonderfully en- 

 dowed with the power of spontaneous movements. Their motions are not occasioned 

 by touch or irritation, but are voluntary and habitual. The small leaflets are more 

 perceptibly active, moving steadily or fitfully, upward or downward or gyrating in 

 circles, during the hours of sunshine. The large leaflet is quietly erect during the 

 day, but slowly falls to a pendant position in the night. 



