VOL. II.] 



MAPLE FAMILY. 



397 



i. A. saccharinum. 



2. A. 



3. A. 



rubrum. 

 Drummondii. 



4. A. Saccharum. 



5. A. nigrum. 



6. A. glabrum. 



Pen nsylvanicum, 



spicatum. 



Negundo. 



Soft or White Maple. (Fig.. 2372. ) 



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, a-celled; styles 2, inserted between the lobes. Fruit 

 of 2 long-winged samaras, joined at the base and i-seeded (rarely 2-seeded). 

 Seeds compressed, ascending; cotyledons thin, folded. 



The family consists of the following genus and Dipteronia Oliver, of central Asia, which dif- 

 fers from Acer in the samara being winged all around. There are about 100 species of Maples. 



i. ACER L. Sp. PI. 1055. 1753. 



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. 

 Petals present; ovary glabrous ; samaras incurved. 



Leaves pale and glabrous or but slightly pubescent beneath. 

 Leaves densely whitish-pubescent beneath ; southern. 

 Flowers corymbose, lateral, unfolding with the leaves. 

 Flowers long-pedicelled, drooping; large trees. 

 Leaves pale and nearly glabrous beneath. 

 Leaves green and pubescent, at least on the veins, beneath. 

 Flowers short-pedicelled, erect; shrub or small tree; western. 

 Flowers racemed, terminal, unfolding after the leaves. 

 Racemes drooping; leaves finely serrate. 

 Racemes erect; leaves coarsely serrate. 

 Leaves pinnate. 



i. Acer saccharinum L. Silver Maple. 



Acer saccharinum L. Sp. PI. 1055. 1753- 



Acer dasycarpum Ehrh. Beitr. 4: 24. 1789. 



Acer eriocarpjtm Michx. Fl. Bor. Am. 2: 253. 1803. 



A large tree with flaky bark, maximum height of 

 loo-i2O 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 above, 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- 

 ritory. The samaras are frequently unequally developed. 

 Wood hard, strong, light colored; weight per cubic foot 

 32 Ibs. Used for furniture and floors. Maple sugar is 

 made from the sap in small quantities. Feb.-April. 



2. Acer rubrum L/. Red, Scarlet or Water 



Maple. Swamp Maple. (Fig. 2373.) 

 Acer rubrum L. Sp. PI. 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 // -i2 // 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 Ibs. Used for furniture, gun-stocks, etc. 

 Foliage crimson in autumn. Ascends to 4000 ft. in 

 Virginia. March-April. Variable. 



