114 THE FOREST TREE CULTURIST. 
Northern States and Canadas. There is a variety of this 
species, P. condicans, or Balm of Gilead, which is quite 
scarce in its wild state, but common as an ornamental 
tree. There are several foreign species cultivated in this 
country, such as the well-known Lombardy Poplar (P. dila- 
tata), and the Abele or White Poplar (P. alba), often 
called Silver Maple, as the leaves resemble the Maple in 
shape, and are covered with a white silky pubescence. It 
produces an immense number of suckers, consequently it 
becomes very troublesome, especially when planted on 
lawns. It grows very rapidly, and is quite ornamental ; 
but there are many other kinds equally as beautiful which 
do not possess that very perplexing habit of producing 
suckers. 
Quercus. (Oak.) 
This is another genus containing a large number of 
species and varieties, among which are some of our most 
valuable timber trees. It would be impossible for me to 
fully describe them without employing the peculiar lan- 
guage and phrases used by botanists, which I fear would 
be understood only by very few readers. I shall therefore 
only notice a few of the most valuable species. The nuts — 
or acorns of most of-our Northern species ripen in the 
autumn of the first year; but the evergreen oaks of the 
South, as well as some of our Northern species, do not 
come to maturity until the end of the second year. 
The forms of the leaves are variable ; some are simple, 
resembling the Chestnut—these are called Chestnut Oaks, 
while others have deeply lobed leaves; the indentation or 
scollop is termed a sts, hence the name, sinuate-lobed. 
