280 TREES OF MINNESOTA. 



Genus ALNUS. 



A genus comprising five species in the Northern States, two 

 of which are in Minnesota. Flowers monoecious, both kinds 

 in catkins pendulous when expanded. Apetalous, calyx usually 

 four-parted. Fruit a winged or wingless minute flat nut. Flow- 

 ers appearing before, with or after the leaves. The species here 

 referred to is one of the smaller and least valuable of the genus. 

 The Alnus glutinosa of Europe makes a large timber tree, grow- 

 ing to the height of seventy feet, and Alnus oregona of the Pa- 

 cific slope sometimes attains a height of eighty feet and a diam- 

 eter of three feet. The specius of Alnus produce soft, straight- 

 grained wood which soon decays, but is of great durability 

 when placed underground or in water. In some places it is 

 largely grown for making charcoal, which is used for inferior 

 kinds of gunpowder. Bowls and other domestic utensils are 

 also made of its wood. The bark and cones are astringent, 

 and are used in tanning leather and in medicine. 



Alnus incana. Speckled or Hoary Alder. 



Leaves oval or ovate, finely dentate, dark green above, pale 

 or glaucous, with some pubescens beneath, veins prominent on 

 lower surface. Catkins appearing much before the leaves; 

 staminate catkins conspicuous in autumn and winter, one and 

 one-half to three inches when unfolded; pistillate catkins about 

 one-half inch long when expanded, but are protected in buds 

 during winter. The fruit is a small cone, and opens in autumn 

 and early winter, and generally remains on the tree until spring. 

 The seed is flat, roundish, with a hard margin. A shrub or 

 small tree eight to twenty-five feet high. 



Distribution. Newfoundland west to the Rocky Mountains 

 and throughout Canada, south to Nebraska and Pennsylvania. 

 Also in Europe and Asia. Generally found in moist places. 



Propagation. By seeds. 



Properties of wood. Light, soft, brittle, not strong. 



Uses. Seldom used in this country for any purpose, but the 

 wood is undoubtedly of value for charcoal for the manufacture 

 of inferior kinds of gunpowder. As a shrub for use in land- 

 scape gardening in wet places it is of some value. 



