252 TREES OF MINNESOTA. 



Uses. The Choke Cherry is a very handsome tree when 

 covered with its abundant racemes of pure white flowers and 

 also when in fruit, but generally it is so disfigured by Black 

 Knot as to make it unsightly. The fruit is used in large 

 quantities by the French Canadians and was formerly an 

 important article of food among the northern Indians and is 

 now used to some extent in the western states. In Minnesota 

 and the Dakotas there is a form that is much superior to the 

 common Choke Cherry in that it has larger, less astringent 

 fruit. Some authors make it a separate species, (.I*runu.x 

 demissa, ) but Prof. Sargent regards it as a variety whose 

 variations are due to the drier climate of the mid-continental 

 states. 



LEC-f UMI]S r O8A K. 



3r>ea Family. 



Distinguished by the butterfly-shaped ( occasionally reg- 

 ular) corolla, usually accompanied by ten monadelphous or 

 diadelphus stamens (rarely distinct); fruit a legume: leaves 

 alternate, compound with stipules. 



A large and important family, comprising trees, shrubs 

 and herbs. Some of our most important agricultural plants 

 belong here, such as the pea, bean, clover, alfalfa, vetch, pea- 

 nut, etc.. and among shrubs the Siberian Pea Tree (Caragana ), 

 Cytisus, Bladder-senna (Colutea) and Wistaria. Important 

 trees belonging here that are beyond our range are the Yel- 

 low-wood (Cladrastis), Sophora, Laburnum. Mesquit and 

 Red Bud* (Cercis). 



Genus GLEDITSIA. 



Gleditsia triacanthos. Honey Locust. Threethorn 

 Acacia. Black Locust. 



Leaves evenly once or twice pinnately compound; thorns 

 very stout, from 2 to 12 inches in length, and usually sending 

 out two thorns as branches; but in some sections, notably in 



* Perhaps found in Southern Minnesota. 



