Minnesota Plant Life. 253 



of their branches, and by the Httle, oval, flattened fruits with 

 wings on each side or extending entirely around the middle. 

 The wood of the elm is tough and is employed for ox-yokes, 

 the handles of tools and portions of farm machinery. The inner 

 bark of the slippery elm is mucilaginous and is thought to have 

 some medicinal virtue. It is frequently gathered by children. 



Hackberries. The hackberry, which in its flowers and foli- 

 age much resembles the elms, is distinguished by the produc- 

 tion of a berry-like nut. It is abundant throughout the south- 

 ern part of the state and occurs in a few localities far to the 

 north ; as for example, on Sable island. Lake of the Woods. 

 The trees are valuable shade trees and are common along the 

 streets of towns and villages. 



Mulberries and hops. The mulberries are represented in 

 Minnesota by the red mulberry — a species reported from the 

 southern part of the state. It is a tree with fruits superficially 

 resembling those of the red raspberry. These are not, however, 

 like those of the raspberry, produced from a single flower, but 

 are rather aggregates of fruits like the spikes of the birch, or 

 the catkins of the poplar. The foliage of a mulberry is not 

 unlike that of the elm. The fruit-clusters are edible and the 

 tree is both ornamental and valuable in cultivation. The com- 

 mon hop, related to the mulberries, is a twining vine with rough 

 stem and foliage, and found in thickets and woodsides through- 

 out the state. It is more abundant in the central and northern 

 portions of the state than southward. The general appearance 

 of the fruiting area is like that of the hop-hornbeam, but the 

 floral structure is in most of the essential details like that of the 

 mulberries. Hops are of value in the manufacture of yeasts and 

 have besides a distinct medicinal value. They are gathered as 

 herbs in Minnesota but not, so far as has been learned, on a 

 commercial scale. 



Hemp. The hemp, introduced from Asia, is a very abund- 

 ant roadside weed and a denizen of waste fields throughout the 

 state. It is a robust annual herb, growing to a height of more 

 than ten feet, forming thickets, and really becoming a sort of 

 herbaceous tree. The inner fibrous bark is exceedingly tough 

 and is pounded out of the stem by special machinery and con- 

 verted into rope and mattings. It is not generally employed 



