WILLOW FAMILY 
Swamp Cottonwood, Populus heterophylla. Leaves 4! to 7 
long. 
Leaf Buds.— 
Slightly resinous, 
ovate, acute, Cov- 
ered with bright red 
brown scales, one- 
fourth an inch long 
and half the size of 
the flower-buds. 
Leaves.—Alter- 
nate, four to seven 
inches long, two to 
three inches broad, 
broadly ovate, cor- 
date or truncate or 
rounded with a small 
sinus at base, finely 
or coarsely crenate- 
ly-serrate with in- 
curved. glandular 
teeth, acute, or short 
pointed or rounded 
at apex; midrib and veins conspicuous, and sometimes downy. 
They come out of the bud involute, covered with thick white tomen- 
tum, when full grown are dark green above pale and smooth be- 
neath. 
slender, tomentose or smooth, two and one- 
half inches long; stipules caducous. 
flowers.—March, April. Staminate am- 
ents are broad, densely flowered, erect at 
first but finally pendulous, two to two and 
one-half inches long with stout, brittle, hairy 
stems. Their scales are narrowly oblong- 
ovate, brown, divided into many narrow 
light red brown lobes and falling as the am- 
ents lengthen. Stamens, twelve to twenty, 
with slender filaments and large dark red 
anthers, are inserted on an oblique, slightly 
concave disk, with spreading border. Pis- 
tillate aments few-flowered, one to two 
inches long; ovary ovoid, terete or three- 
angled; style short, stout with two or three 
dilated, two or three-lobed stigmas. 
Fruit.—In maturing the fruiting aments 
become four to six inches long, pedicels 
half an inch long; capsules ripen in May, 
are ovate, acute, red brown, two to three- 
valved, one-half an inch lone; seed small, 
dark brown, surrounded by many short, 
silvery white hairs which are often tinged 
with orange. 
420 
In autumn they turn dull yellow or brown. 
Petioles terete, 
Part of the Fruiting Ament 
of Swamp Cottonwood 
Populus heterophylla. 
