422 PRACTICAL ARBORICULTURE 
The seed must be scalded, or subjected to heat to soften the heavy shell cover- 
ing the seed. 
Seedlings are better than suckers for a plantation. : 
THE ASPEN. 
This is essentially a production of high altitudes and Northern latitudes, 
growing in the higher Rocky mountains, covering many slopes and filling the 
valleys at the head of every water course. 
The seed is produced with the same profusion as that of the cottonwood, 
which is of the same family, and the young growths are very dense where the 
location is favorable, often more than a million to each square mile. For this 
ASPEN, 32 INCHES DIAMETER 
reason the Aspen is usually of quite small size, seldom attaining a diameter of more 
than six inches in such thickets. As the groves become thinned in time they in- 
crease rapidly in size, and where the trees are isolated, they become fine, large 
trees. 
Our cut shows a thicket of Aspens, among which spruce and fir are protected. 
The one Aspen in foreground is thirty-two inches in diameter, having a long trunk 
carrying its size to a great height. This is upon the lands of the Colorado Fuel 
and Iron Company, on the Sangre de Christo Range, Colorado, at the elevation 
of ten thousand feet. 
Nearby are groves estimated to contain 640,000 trees per square mile, rang- 
ing from eight to sixteen inches diameter—each of which would make from three 
to five lengths of mine timbers. 
