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28 TREES OF MINNESOTA. 
Propagation.—Grown from seeds, which should be stratified 
over winter and sown in the spring. 
Propertics 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. 
