ACERINE.E 63 



Ovary 2-lobed, 2-celled ; style 1 ; stigmas 2. Fruit of two 

 indehiscent winged carpels (samara,) each 1-celled, with 1 

 or 2 seeds. Seeds erect ; albumen none ; embryo curved or 

 convolute, with foliaceous wrinkled cotyledons and an inferior 

 radicle. 



Ti-ees, with opposite, simple, rarely pinnate leaves. Flowers 

 often polygamous, sometimes apetalous. 



1. ACER. Linn. 



Flowers mostly polygamous. Calyx 5-lobed, sometimes 

 5-parted. Stamens rarely 5, often 7 9. Samara 2, wing- 

 ed, united at base, by abortion 1-seeded. 



Octandria. Monogynia. 



* Flowers in corymbs or fascicles. 



1. A. rubrum Linn. : leaves generally 5-lobed, cordate at the base, 

 unequally and incisely toothed, glaucous beneath ; the sinuses acute ; 

 flowers aggregated in about fives, on rather long pedicels ; germs gla- 

 brous. 



HAB. Moist woods. Can. to Flor. April. A tree from 2050 

 feet high. Flowers 5-pe tailed, pentandrous. Red Maple. 



. 2. A. eriocarpum Mich. : leaves palmately 5-lobed, truncate at the 

 base, smooth and whitish-glaucous beneath ; sinuses obtuse ; lobes 

 acuminate, incisely toothed ; flowers aggregated, on short pedicels ; 

 germs tomentose. A. dasycarpum WUld. 



HAB. Banks of streams. Can. to Geor. April, May. A large 

 tree. Flowers greenish, pentandrous, apetalous. 



While or Soft Maple. 



3. A. barbatum Mich. : leaves ovate-cordate, with 3 short lobes, un- 

 equally serrate, glaucous beneath and pubescent on the nerves ; corymbs 

 sessile ; peduncles hairy ; those of the sterile flowers branched ; of 

 the fertile simple ; calyx bearded within ; fruit smooth ; wings erect. 

 A. carolinianum Walt. 



HAB. Cedar swamps. N. S. to Car. April. A small tree. 

 Leaves small. Flowers pale green. Calyx densely bearded with- 

 in. 



4. A. saccharinum Linn. : leaves palmately 5-lobed, subcordate at 

 base, petioled, glaucous beneath ; lobes acuminate ; peduncles corym- 

 bose, loose, nodding, hairy ; fruit glabrous ; wings divergent. 



HAB. In woods. Can. to Geor. W. to Miss. April. A large 

 tree. Flowers yellowish, on long filiform peduncles. Petioles 

 smooth. Valuable for its timber and for the sugar obtained from 

 its sap. Sugar Maple. 



5. A. nigrum Mich. : leaves palmately 5-lobed, cordate, with the 

 sinus closed, pubescent beneath ; lobes divaricate, sinuate-dentate ; 



