114 WOODY PLANTS OF MASSACHUSETTS. 
hemisphere. A few are found upon the mountains within the 
tropics, but are unknown in the valleys. 
It was formerly considered a part of the much larger family 
of Amentacese. As now constituted, it is a strictly natural 
family. The trees which belong to it are remarkable for their 
thick and rugged bark, and for the great abundance of the prin- 
ciple of tannin which it contains. They have large and strong 
roots, penetrating very deep, or extending very far, horizontally, 
beneath the surface, and sometimes, as in the case of the oak, 
both. The trunks are distinguished for their massiveness, and 
for the weight, strength, and, in most cases, the durability of 
their wood, and its preéminent importance in the arts. Their 
branches are long and irregular, and form a broad head of 
greater depth than belongs to the trees of any other family. 
The buds are fitted for a climate with severe winters, the 
plaited or folded leaves being covered by imbricate, external 
scales, and, often, still further protected by a separate, downy 
scale, surrounding each separate leaf. ‘T'he leaves are plane, 
and alternate, and usually supported by a footstalk, at the base 
of which are two slender leaflets or stipules, which, for the most 
part, fall off, as the leaf expands. 
The fruit is valuable as food to man and the animals depend- 
anton him. The fruits of the chestnut and hazel have been 
long cultivated on the Eastern continent, and much improved 
in size and quality. All are doubtless susceptible of it; but the 
life of these trees is so long, in comparison with the duration of 
man, that experiments for this purpose must be carried on by 
successive generations. 
‘This family includes trees and shrubs whose male and female 
flowers are separate, but on the same trunk. The male flow- 
ers, which appear early in the spring, are in long tassels called 
aments or catkins, made up of a great number of separate, cup- 
shaped, jagged scales or membranous leaves, to the base or side 
of which, beneath or within, are attached the stamens, from 
five to twenty in number. ‘The female flowers are usually 
bud-shaped. The ovaries or seed-vessels are seated within a 
leathery cup or involucre, are surrounded by an irregularly 
toothed calyx, and tipped with several stigmas. They contain 
