2Q2 



Minnesota Plant Life. 



of extra large prickles just below the stipules at the base of 

 each leaf. 



This description does not extend over all the wild roses of 

 the state, but without going into technical details gives an idea 

 of their differences. All the roses are marked by a special 

 type of fruit which may be compared, perhaps, to a strawberry 

 turned inside out ; that is to say, the nutlets or fruits are aggre- 

 gated not upon a convex, but upon a concave receptacle. The 

 calyx grows up around this concave end of the flower, and the 



FIG. 143. Sand-cherry in fruit. After Bailey. Bull. 70, Cornell Ag. Kxpt. Station. 



nutlets are inclosed within its red and fleshy substance. Some 

 roses have the fruits, or hips, as they are called, protected by 

 a growth of prickles, while in others they are smooth. 



Plums, peaches and cherries. A well-marked sub-family of 

 roses includes the plums, cherries, peaches, apricots and al- 

 monds. These are all trees or shrubs with bitter bark and 

 foliage. The bark, leaves, and seeds contain small quantities 

 'of prussic acid, a substance which has, when chemically pre- 

 pared, about the same odor as the kernel of a peach stone. The 

 flowers are of the ordinary rose type, except that there is only 



