Vot. II.] * MAPLE FAMILY. 397 
5-parted, the segments imbricated. Petals of the same number, or none. Disk 
thick, annular, lobed, sometimes obsolete. Stamens 4-12, often 8; filaments 
filiform. Ovary 2-lobed, 2-celled; styles 2, inserted between the lobes. Fruit 
of 2 long-winged samaras, joined at the base and 1-seeded (rarely 2-seeded). 
Seeds compressed, ascending; cotyledons thin, folded. 
The family consists of the following genus and Di//eronza Oliver, of central Asia, which dif- 
fers from Acer in the samara being winged all around. ‘There are about 100 species of Maples. 
PO ACERLT) Spr Pl TO55e. elses 
Besides the following, some 5 others occur in southern and western North America. 
Leaves simple, palmately lobed. 
Flowers in dense sessile lateral clusters, unfolding before the leaves. 
Petals none; ovary tomentose; samaras divergent. 1. A. saccharinum. 
Petals present; ovary glabrous; samaras incurved, 
Leaves pale and glabrous or but slightly pubescent beneath. 2. 4. rubrum. 
Leaves densely whitish-pubescent beneath; southern. 3. A. Drummondit, 
Flowers corymbose, lateral, unfolding with the leaves, 
Flowers long- pedicelled, drooping; large trees. 
Leaves pale and nearly glabrous beneath. 4. A. Saccharum, 
Leaves green and pubescent, at least on the veins, beneath. 5. A. nigrum. 
Flowers short-pedicelled, erect; shrub or small tree; western, 6. A. glabrum. 
Flowers racemed, terminal, unfolding after the leaves. 
Racemes drooping; leaves finely serrate. 7. A. Pennsylvanicum. 
Racemes erect; leaves coarsely serrate. 8. A. spicatum. 
Leaves pinnate. g. A. Negundo. 
Acer saccharinum I,. Silver Maple. Soft or White Maple. (Fig. 2372.) 
em saccharinum I,. Sp. Pl. 1055. 1753- 
Acer dasycarpum Ehth. Beitr. 4: 24. 1789. 
Acer ertocarpum Michx. FI. Bor, Am. 2: 253. 1803. 
A large tree with flaky bark, maximum height of 
too°-120° and trunk diameter of 3°-5°. Leaves 4/— 
6’ long, deeply 5-lobed, the lobes rather narrow, 
acuminate, coarsely and irregularly dentate, trun- 
cate or slightly cordate at the base, green aboye, sil- 
very white and more or less pubescent beneath, espe- 
cially when young; flowers greenish, in nearly sessile 
lateral corymbs much preceding the leaves; petals 
none; fruiting pedicels elongating; samaras pubescent 
when young, divaricate, at length 2’ long, the wing 
often 6’ wide. 
Along streams, New Brunswick to Florida, west to 
southern Ontario, Dakota, Nebraska and the Indian Ter- 
titory. The samaras are frequently unequally developed. 
Wood har¢é, strong, light colored; weight per cubic foot 
32 lbs. Used for furniture and floors. Mz aple sugar is 
made from the sap in small quantities. Feb,—April. 
2. Acer rubrum J,. Red, Scarlet or Water 
Maple. Swamp Maple. (Fig. 2373.) 
Acer rubrum I,. Sp. Pl. 1055. 1753. 
A large tree with flaky or smoothish bark, maxi- 
mum height about 120° feet and trunk diameter 3°- 
4%°. ‘Twigs reddish; leaves 3/-4/ long, cordate at 
the base, sharply 3-5-lobed, the lobes irregularly 
dentate, acute or acuminate, green above, pale and 
generally whitish beneath, often more or less pubes- 
cent along the veins; flowers reddish or yellowish, 
in sessile lateral clusters much preceding the 
leaves; petals narrowly oblong; stamens 3-6; fruit- 
ing pedicels elongating; samaras glabrous, slightly 
incurved, 9/’-12’’ long, the wing 3//-4’” wide. 
In swamps and low grounds, New Brunswick to 
Manitoba, south to Florida and Texas. Wood hard, 
not strong; color light reddish brown; weight per 
cubic foot 38 lbs. Used for furniture, gun-stocks, etc. 
Foliage crimson in autumn. Ascends to 4ooo ft. in 
Virginia. March-April. Variable. 
