306 Trees for Shade and Ornament 
some extent and near houses, giving a light shade. It is adaptiyc 
to light, deep, sandy soils, such as dunes, but also to more compact 
soils, and is a very thrifty and rapid grower. 
P. Padus Linn. (282), English Bird Cherry. A small flat-headed 
tree or shrub, otherwise similar to the foregoing, blooms earlier (May), 
but has less pleasing foliage. 
P. Pennsylvanica Linn. (283), Pin Cherry or Bird Cherry, is an 
interesting small native tree, often hardly more than a bush, distributed 
over almost the whole northern part of the continent, springing up 
freely after forest fires. Its small white flowers, lively green foliage, 
but more particularly its cherry-red fruit, the size of a pin or pea, are 
its attraction. It grows in any dry soil. 
P. Mahaleb Linn. (284), Mahaleb Cherry, a small slender tree 
(15 to 20 feet) from the Caucasus and middle Europe, hardy to 
Ottawa, is more ornamental than the Bird Cherry, by reason of its 
apricot-like glossy foliage of pale gieen color, on slender but abun- 
dant sprays, and with as fine flower and fruit as the foregoing, the 
flowers being fragrant and in umbels (May, June). 
OAK 
Quercus. This genus, of not less than two hundred and seventy-five 
species, over fifty of which are found in North America, represents 
among the broad-leaf trees what the pine represents among the con- 
ifers, in usefulness and in wide distribution, but it excels in number of 
species and in ornamental value, ranging in size from majestic trees 
to small shrubs, with a variety of foliage and of form hardly equaled 
by any other single genus. The oaks are inhabitants of the northern 
temperate zone, occurring, however, also in the tropics in high altitudes, 
and are extremely adaptive to soils from the driest to the swamp. The 
deciduous ones are mostly hardy in the north, the evergreen not north 
of Washington. They are the embodiment of sturdiness and persist- 
ency, holding on to life wherever there is a chance, with remarkable 
recuperative power. They are light-needing, but will persist in the 
shade for a long time. Although normally having a tap-root system, 
they readily adapt themselves, permit any amount of pruning at top 
and root, so that mere root stumps may be transplanted and grow into 
trees. They grow at a more rapid rate than they are usually credited, 
but, to be sure, the majestic, broad-crowned beauties are centenarians. 
