ACERACEAE. 6<DJ 



Family 9. ACERACEAE St. Hil. 



Maple Family. 



Trees or shrubs, with water}- often saccharine sap, opposite simple and 

 palmately lobed (rarely entire) or pinnate leaves, and axillary or terminal 

 cymose or racemose regular polygamous or dioecious flowers. Calyx gener- 

 ally 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 i-seeded (rarely 2-seeded). Seeds compressed, ascending ; cotyledons 

 thin, folded. The' family consists of the following genus and Dipteronia 

 Oliver, of central Asia. There are about 100 species of Maples. 



1 ACER L. (See Appendix.) 



[Ancient name of the maples.] 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. saccharintitn. 



Petals present ; ovary glabrous ; samaras incurved. 



Leaves pale and glabrous or but slightly pubescent beneath. 



2. A. rubrum. 

 Leaves densely whitish-pubescent beneath ; southern. 



3. A. Drummondii. 

 Flowers corymbose, unfolding with the leaves. 



Flowers long-pedicelled, drooping ; large trees. 



Leaves pale and nearly glabrous beneath. 4. A. Saccharutn. 



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



5. A. nigrum. 

 Flowers short-pedicelled, erect; shrub or small tree. 6. A. glabrnm. 

 Flowers racemed, terminal, unfolding after the leaves. 



Racemes drooping; leaves finely serrate. 7. A. Pennsylvanicum. 



Racemes erect ; leaves coarsely serrate. 8. A. spicatmn. 



Leaves pinnate. 9. A. Xegundo, 



1. Acer saccharinum L. Silver Maple. Soft or White Maple. (I. F. f. 

 2372.) A tree with flaky bark. Leaves 1-1.5 dm. long, deeply 5-lobed, the lobes 

 rather narrow, acuminate, coarsely and irregularly dentate, truncate or slightly cor- 

 date at the base, green above, silvery white and more or less pubescent beneath; 

 flowers greenish or red; fruiting pedicels elongating; samaras at length 5-7 cm. 

 long, the wing often 1.2 cm. wide. Along streams. N. B. to Fla.. S. Ont., Dak.. 

 Neb. and the Ind. Terr. Yields maple sugar in small quantities. Feb. -April. 



2. Acer rubrum L. Red. Scarlet or Water Maple. Swamp Maple. 

 (I. F. f. 2373.) A tree with flaky or smoothish bark. Twigs reddish; leaves 

 7-10 cm. long, cordate at the base, sharply 3-5 -lobed. the lobes irregularly den- 

 tate, acute or acuminate, green above, generally whitish beneath; flowers reddish 

 or yellowish: petals narrowly oblong; stamens 3-6; fruiting pedicels elongating; 

 samaras 1.8-2.5 cm - l° n g? the wing 6-8 mm. wide. In swamps and low grounds, 

 N. B. to Manitoba, Fla. and Tex. Foliage crimson in autumn. March-April. 



3. Acer Drumm5ndii H. & A. Drummond's Maple. (I. F. f. 2374.) 

 Similar to the preceding. Leaves 7-15 cm. long, thicker, 3-lobed. or sometimes 

 5-lobed, obtuse or cordate at the base, the lobes shorter, broader, acute or acumi- 

 nate; young twigs and petioles more or less tomentose; fruiting pedicels 2.5-5 cm - 

 long; samaras 3.75-6.25 cm. long, the wing 1-2 cm. broad at middle. In swamps, 

 southern Mo. to Ga.. Fla. and Tex. Fruit scarlet, ripening in March or April. 



4. Acer Saccharum Marsh. Sugar or Rock Maple. Sugar-tree. (I. F. 

 f. 2375.) A large tree. Leaves 7.5-15 cm. long, dark green above, cordate or 

 truncate at the base. 3-7-lobed, the lobes acuminate, irregularly sinuate, the sin- 

 uses rounded; flowers in sessile corymbs, greenish yellow; petals none; samaras 

 glabrous, slightly diverging, 2.5-3.75 cm. long, the wing 6-10 mm. wide. In rich 



