The Maples 



F. Lobes of leaves blunt, pubescent beneath; 

 margins wavy, 



(A. Floridanum) sugar maple 

 FF. Lobes of leaves sharp, smooth beneath; 

 margins toothed. 



(A. Saccharum) sugar maple 

 EE. Leaves green beneath, pubescent. 



F. Branchlets slender; leaves thin, bright 

 yellow-green. 



(A. leucoderme) sugar maple 

 FF. Branchlets stout, orange coloured; leaves 

 thick, drooping, dull green. 



{A. nigrum) black maple 

 DD. Corymbs on short stalks; leaves 3-lobed, pale 

 and pubescent beneath; lobes with large 

 rounded teeth. 



{A. grandidentatd) large-tooth maple 

 AA. Leaves pinnately compound, leaflets 3 to 5; flowers dioe- 

 cious. {A. Negundo) box elder 



Opposite leaves palmately veined and lobed, and paired 

 keys with long wings — these characters are the hallmark of the 

 maple' family the world over. No amount of "improvement" 

 blots these out of the most ultra new variety. No other tree has 

 both leaves and fruits likely to be confused with a maple's. 



The genus Acer comprises between sixty and seventy species, 

 well scattered over the Northern Hemisphere. China and Japan 

 are the original home and the centre of population for them, 

 having about thirty native maples. Twelve species are found 

 in the Himalayas, and twelve in Europe and Asia Minor. Nine 

 are native to North America. Of these, two are on the Pacific 

 coast, one among the Rocky Mountains, five in the eastern half 

 of the continent, and there is one species "at large." 



Red or Scarlet Maple, Swamp Maple (Acer rubrum, 

 Linn.) — A spreading, symmetrical tree, 80 to 120 feet high, 

 oftener less, slender with erect branches. Bark flaky, in plates, 

 dark grey; paler branches; twigs red. fVood pale, brownish 

 red, hard, close grained. Buds opposite, blunt, red; flower buds 

 clustered on side spurs. Leaves variable in size, 3 to 6 inches 

 long, not so wide; with 3 to 5 triangular lobes, separated by 

 triangular sinuses; margins twice cut-toothed; lining whitish, 

 often downy; petioles long, slender, often red; autumn colours 

 scarlet and crimson. Flowers: pistillate red, staminate orange, 



?68 



