248 ACERACEiE. Acer. 



" Rocky Mountains, on Bear River of Timpanagos. — A shrub or low tree, 

 with pale smooth branches. Leaves smaller than in A. saccharinum, gla- 

 brous and somewhat shining above, minutely pubescent especially on the 

 veins beneath ; lobes short, not in the least acuminate ; the middle one with 

 two blunt teeth oh each side; the lateral with a single large diverging den- 

 ture. Pedicels pubescent above. Fruit turgid, glabrous ; the wings less than 

 an inch long, semioval, slightly attenuated below, somewhat divergent." Nutt. 

 — To this species we refer with little hesitation A. barbatum, Dougl. (not 

 of Michx.), which was found in "Valleys near springs on the west side of 

 the Rocky Mountains, near the sources of the Columbia." We have not 

 seen the flowers, but there is little doubt that the inflorescence is the same as 

 in A. saccharinum. 



8. A. saccharinum (Linn.) : leaves truncate and subcordate at the base 

 (whitish and minutely pubescent or glabrous beneath), 3-5-lobed, with 

 the sinuses obtuse ; lobes with a slender acumination, coarsely and spar- 

 ingly sinuate-toothed ; sepals bearded at the apex within ; petals none ; fruit 

 glabrous, on long nodding pedicels; the wings dilated above, suberect or 

 slightly diverging. — Wang. Amer. p. 36, ^.11; Michx.fi. 2. p. 252; Pursh, 

 fi.l. p. 266 ; Mich.v. f. sylv. 1. t. 42; Ell. sk. 1. p. 450; Ihrr. ! fi. 1. p. 

 397; Hook. fl. Bor.-Am. 1. p. 113. A. saccharum. Marsh, arhust. p. 4. 



/?. nigrum: leaves pale green beneath, the veins of the lower surface and 

 petioles minutely villous-pubescent ; wings of the fruit a little more diverg- 

 ing. — A. nigrum, Mich.T.f. sylv. 1. t. 43. 



In rather dry woods, Canada! to the mountains of Georgia! west to Ar- 

 kansas ! and the Rocky Mountains. April-May. — Tree 50-80 feet high ; 

 the trunk sometimes 2-3 feet in diameter ; the wood compact and close-grain- 

 ed : the sap contains sugar. Leaves 3-5 inches in length, generally wider 

 than long, on slender petioles, green and slightly lucid above, whitish and at 

 first very pubescent, at length minutely pubescent or nearly glabrous, except 

 on the veins beneath ; lobes diverging, usually three principal ones with two 

 smaU entire ones at the base. Flowers pale greenish-yellow, on pendulous 

 villous pedicels. Wings of the fruit about an inch long, semi-obovate. — Su- 

 gar-Maple. — Two accidental forms of arrangement of the woody fibre, &c. 

 furnish the Curled-Maple and the Birds-eye- Maple of cabinet-makers. 

 We are unable clearly to distinguish the Black Sugar-Maple from the pre- 

 sent species. 



♦*♦* Pedicels in fascicles, evolved from lateral aggregated leafless buds: flowers 

 f receding the leaves. 



9. A. dasycarpum (Ehrh.) : leaves subcordate or often truncate at the 

 base (white beneath), deeply 5-lobed, with the sinuses rather obtuse ; lobes 

 acute, unequally incised and toothed, entire towards the base ; pedicels short 

 and thick; petals none ; fruit tomentose when young, nearly glabrous when 

 old, with very large upwardly dilated somewhat diverging wings. — " Ehrh. 

 heitr. 4. p. 24" ; ^Villd. sp. 4. p. 985; Nutt. ! gen. 1. p. 252 ; ^Ell. sk. 1. p. 

 449; Torr.! fl. 1. p. 396; Hook. fl. Bor.-Am. \. p. 113. A. eriocarpum, 

 Mich.T. ! fi. 2. p. 253 ; Desf. in ann. mus. 7. t. 25 ; Michx. f. sylv. 1. 1. 40 ; 

 DC. prodr. 1. p. 595; Darlingt. fl. Cest. ed. 2. p. 245. 



Banks of rivers, Maine and Vermont ! to the upper and middle parts of 

 Georgia ! west to Lake Michigan and Arkansas ; rare north of lat. 43^ ; most 

 abundant in the Western States. March-April. — Trunk low, 2 (in the 

 Western States sometimes 8-9) feet in diameter: wood white and soft, not 

 durable : sap less sweet than that of the Sugar-Maple. Leaves on long pe- 

 tioles, at first tomentose, finally glabrous, as broad as long ; the lobes often 

 somewhat 3-lobed. Pedicels in flower 2-3 lines, in fruit an inch, long. Flow- 

 ers small, pale yellowish-purple. Stamens 3-6. Ovary with no glands at the 

 base. W'ings of the fruit 2-3 inches long when mature, slightly falcate. 



