328 TREES OF MINNESOTA. 



Propagation. Grown from seeds, which should be stratified 

 over winter and sown in the spring. 



Properties of wood. Heavy, hard and close grained, but not- 

 strong. It is light brown in color, with a thick light colored 

 sapwood. The specific gravity 0.6951; weight of a cubic foot 

 43.42 pounds. 



Uses. The Choke Cherry is a very handsome tree when cov- 

 ered 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 (Prunus demissa), but Professor 

 Sargent regards it as a variety whose variations are due to the 

 drier climate of the mid-continental states. 



LEGUMINOSAE. PEA FAMILY. 



Distinguished by the butterfly-shaped (occasionally regular) 

 corolla, usually accompanied by ten monadelphous or diadelphus 

 stamens (rarely distinct); fruit a legume; leaves alternate, com- 

 pound 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, peanut, etc., 

 and among shrubs the Siberian Pea Tree (Caragana), Cytisus, 

 Bladder-senna (Colutea) and Wistaria. Important trees be- 

 longing here that are beyond our range are the Yellow-wood 

 (Cladrastis), Sophora, Laburnum, Mesquit and Red Bud * 

 (Cercis). 



* Perhaps found in Southern Minnesota. 



