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. 
