334 WOODY PLANTS OF MASSACHUSETTS. 
it throws out its branches with a gentle, double curvature, to a 
distance on every side, and forms a broad, round head, of great 
beauty. The trunk is covered with a whitish bark, which, in 
very young trees, is nearly smooth ; on older trees, it is broken 
by deep furrows crossing each other obliquely, into irregular, 
square, or lozenge-shaped plates, and on very old stems becomes 
smooth again from the rough plates scaling off. The bark of 
the branches is smooth, of a grayish green, indistinctly dotted 
with gray; while, on the somewhat stout young shoots, it is of 
a smooth, polished, deep green, with long white dots. 
The leaves are opposite, compound, twelve or fifteen inches 
long, the stalks much swollen at base and at the joinis, round, 
smooth, and tapering. The Jeaflets are usually seven, (five to 
nine,) from three to five inches long and one or two broad, on 
compressed petioles, channelled above, four or five lines long. 
They vary in form from egg-shaped to lance-shaped, elliptic, 
oblong and inversely egg-shaped, tapering to a long point, rather 
acute at base, entire or slightly dentate, or serrate, smooth above, 
very pale or glaucous, and somewhat hairy along the veins be- 
neath. The odd leaflet is on along stalk. The young leaves 
are very downy, but become almost perfectly smooth. The 
buds are short and rust-colored, smooth; terminal buds large. 
The flowers are in opposite fascicles or bunches, near the ends 
of the branches, in the axils of the last year’s leaves. The 
fertile flowers are on a smooth, branched, tapering, purplish 
rachis, with opposite branches, each branch terminating in a 
flower. Calyx deeply two-parted, the parts divided slightly. 
Ovary flattened, elliptic; style tapering; stigma bifid. The 
footstalks have two opposite scales, like bud-scales, near the 
base, and beneath each ramification. In the fertile flowers, the 
two sterile stamens, when present, are opposite, at the base of 
the ovary. ‘The staminate are in close, dense, much-branched 
fascicles. At the end of each very short branch, in a flat cup 
With four teeth, are two sessile or nearly sessile brown stamens, 
parallel and one eighth of an inch long. The keys or samare 
are on angular, tapering, diverging stalks, dividing by threes, 
and from five to seven inches long. The keys are one and a 
half inches long, cylindrical at the base, which is surrounded 
