632 TREES OF NORTH AMERICA 



of the trunk thin, smooth, and dark reddish brown. "Wood heavy, hard, close-grained, 

 light brown or often nearly white, with thick lighter colored sapwood. 



Distribution. Borders of mountain streams usually at elevations of 5000-6000 

 above the sea, and northward sometimes descending to the sea-level; head of Lynn 

 Canal, Alaska, over the mountain ranges of western America, extending southward 

 in California along the Sierra Nevada to the west fork of the Kaweah River, and 

 eastward to northwestern Nebraska, the eastern slopes of the Rocky Mountains of 

 Colorado, eastern New Mexico and Arizona; of its largest size on the coast of Van- 

 couver Island and on the Blue Mountains of Oregon; also arborescent in some of the 

 elevated canons of Idaho, New Mexico, and Arizona; usually shrubby. 



Occasionally cultivated in the eastern states, and hardy as far north as eastern 

 Massachusetts. 



6. Acer Saccharum, Marsh. Sugar Maple. Rock Maple. 

 Leaves heart-shaped by a broad sinus, truncate or sometimes wedge-shaped at 

 the base, 3-5-lobed, with rounded sinuses, usually acute sparingly sinuate-toothed 



lobes, 3-5 conspicuous nerves, and reticulate veinlets, when they unfold coated below 

 with pale pubescence, glabrous at maturity, 4' 5' in diameter, often rather coria- 

 ceous, dark green and opaque on the upper, pale on the lower surface, turning in the 

 autumn brilliant shades of deep red, scarlet and orange or clear yellow; their petioles 

 slender, glabrous, l^'-3' long. Flowers appearing with the leaves on slender hairy 

 pedicels 2'-3' long, in nearly sessile umbel-like corymbs from terminal leaf -buds 

 and lateral leafless buds, the staminate and pistillate in separate clusters on the same 

 or on different trees; calyx broadly campanulate, 5-lobed by the partial union of the 

 obtuse sepals, greenish yellow, hairy on the outer surface; corolla 0; stamens 7-8, 

 with slender glabrous filaments twice as long as the calyx in the staminate flower 

 and much shorter in the pistillate flower; ovary obtusely lobed, pale green, covered 

 with long scattered hairs, in the staminate flower reduced to a minute point; styles 

 united at the base only, with 2 long exserted stigmatic lobes. Fruit ripening in the 

 autumn, glabrous, with broad, thin, and usually divergent wings \'-V long; seeds 

 smooth, bright red-brown, \' long. 



A tree, 100-120 high, with a trunk often 3^ in diameter, rising sometimes 

 in the forest to the height of 60-70 without branches, or in open situations devel- 



