FOREST TREES. 93 



in diameter, but only on very favorable situations does it 

 grow to sucb a size. Wood very bard, resembling tbat of tbe 

 Sugar Maple, and one of tbe best and most valuable bard woods 

 found west of tbe Rocky Mountains. Tbe sap is sweet, and 

 yields a fair quality of sugar. Tbis maple occurs in California, 

 from Santa Barbara, and northward, to Wasbiugton Territory. 

 It is a tree well wortby of tbe attention of arboriculturists, 

 East as well as in tbe West ; but tbe seed sbould be procured 

 from Nortbern localities, and from large trees, else tbe plants 

 are likely to be tender and of slow growtb in localities east of 

 tbe mountains. 



A. graudidentatnin. — Mountain Sugar Maple. — Leaves slightly 

 cordate or truncate at tbe base, pubescent beneatb, and rather 

 deeply tbree-lobed; lobes acute with a few sinuous indentations. 

 Flowers few ; the petals nodding. Seed smooth, with small, 

 diverging wings. Tbis species, although closely related to tbe 

 Sugar Maple, does not attain a vcrj^ large size, seldom growing 

 more than thirty feet high. It is found in Arizona, Southern 

 Utah, and on the west side of tbe Mountains, near the head- 

 waters of tbe Columbia, principally in tbe valleys, and near 

 small streams. 



A. glabrnm. — Smooth-leaved Mountain Maple. — Leaves smooth, 

 two to four inches broad, rounded, heart-shaped in outbne, 

 with rather shallow indentations, although occasionally dis- 

 tinctly tbree-lobed ; the lobes doubly serrated, with acute teeth. 

 Flower in large corymbs, on short brancblets ; greenish-yellow. 

 Seeds, with broad-spreading wings, rii^en late in fall. Quite a 

 variable species, both in leaves, color of tbe branches, and form 

 of growth. Tbis si^ecies probably grows at a higher elevation 

 in tbe Rocky Mountains than any other native maple. I have 

 found it abundant in Colorado and New Mexico, at an elevation 

 of ten thousand feet. In exposed situations, on tbe sides of a 

 canyon, it was merely a tall sbi-ub, with many stems springing 

 from tbe same root, probably because frequently killed down 

 in winter ; but where protected by other trees, it assumes an 

 upright form, growing thirty or more feet high. Wood quite 

 hard, and fine-grained, but, as generally found, it is too small 

 for any ijractical use except for firewood. Common in the 

 mountains of Nortbern New Mexico, Colorado, and west to tbe 

 Sierra Nevada, and northward to Vancouver's Island. 



A. Negiuido, or Nogundo aceroides. — Negundo Maple, Box Elder, 

 Ash-leaved Maple. — Although our modem botanists consider 



